diff --git a/.gitignore b/.gitignore
index ae89cac3..ff528eb9 100755
--- a/.gitignore
+++ b/.gitignore
@@ -54,3 +54,4 @@ jspm_packages
 
 # Optional REPL history
 .node_repl_history
+build.cjs
diff --git a/.vscode/launch.json b/.vscode/launch.json
index 2c832a60..c0251804 100755
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -6,7 +6,7 @@
             "request": "launch",
             "name": "Launch Program",
             "program": "${workspaceFolder}/src/butler-sos.js",
-            "runtimeVersion": "20",
+            "runtimeVersion": "18",
             "cwd": "${workspaceFolder}/src",
             "env": {
                 "NODE_CONFIG_DIR": "${workspaceFolder}/src/config",
diff --git a/src/butler-sos.js b/src/butler-sos.js
index c335df22..bbb60f32 100755
--- a/src/butler-sos.js
+++ b/src/butler-sos.js
@@ -22,7 +22,6 @@ import { udpInitUserActivityServer } from './lib/udp_handlers_user_activity.js';
 import { udpInitLogEventServer } from './lib/udp_handlers_log_events.js';
 import { setupAnonUsageReportTimer } from './lib/telemetry.js';
 import { setupPromClient } from './lib/prom-client.js';
-import { verifyConfigFile } from './lib/config-file-verify.js';
 import { setupConfigVisServer } from './lib/config-visualise.js';
 import { setupUdpEventsStorage } from './lib/udp-event.js';
 
@@ -60,25 +59,8 @@ async function mainScript() {
     const globals = await settingsObj.init();
     globals.logger.verbose(`START: Globals init done: ${globals.initialised}`);
 
-    // Verify that the config file has the correct format
-    // Only do this if the command line option no-config-file-verify is NOT set
-    let configFileVerify = false;
-    if (globals.options.skipConfigVerification) {
-        globals.logger.warn('MAIN: Skipping config file verification');
-    } else {
-        configFileVerify = await verifyConfigFile();
-    }
-
-    // If config file verification failed, the previous function would have returned false.
-    // In that case, we should exit the script.
-    if (!configFileVerify) {
-        globals.logger.error('MAIN: Config file verification failed. Exiting.');
-        process.exit(1);
-    }
-
     // Ensure that initialisation of globals is complete
-    // Sleep 5 seconds otherwise to llow globals to be initialised
-
+    // Sleep 5 seconds otherwise to allow globals to be initialised
     function sleepLocal(ms) {
         return new Promise((resolve) => setTimeout(resolve, ms));
     }
diff --git a/src/config/production_template.yaml b/src/config/production_template.yaml
index 3ed9bc04..8bfdaa6c 100644
--- a/src/config/production_template.yaml
+++ b/src/config/production_template.yaml
@@ -3,7 +3,7 @@ Butler-SOS:
   # All configuration items are mandatory, unless otherwise noted.
 
   # Logging configuration
-  logLevel: info          # Log level. Possible log levels are silly, debug, verbose, info, warn, error
+  logLevel: info          # Log level. Possible log levels are silly, debug, verbose, info, warn, error. Case sensitive.
   fileLogging: true       # true/false to enable/disable logging to disk file
   logDirectory: log       # Subdirectory where log files are stored
   anonTelemetry: true     # Can Butler SOS send anonymous data about what computer it is running on? 
@@ -81,7 +81,7 @@ Butler-SOS:
   qlikSenseEvents:                  # Shared settings for user and log events (see below)
     influxdb:
       enable: false                 # Should summary (counter) of user/log events, and rejected events be stored in InfluxDB?
-      writeFrequency: 20000         # How often (milliseconds) should rejected event count be written to InfluxDB?  
+      writeFrequency: 20000         # How often (milliseconds) should event counts be written to InfluxDB?  
     eventCount:                     # Track how many events are received from Sense.
                                     # Some events are valid, some are not. Of the valid events, some are rejected by Butler SOS
                                     # based on the configuration in this file. 
diff --git a/src/globals.js b/src/globals.js
index 83db1e63..31df1b82 100755
--- a/src/globals.js
+++ b/src/globals.js
@@ -16,6 +16,7 @@ import { fileURLToPath } from 'url';
 
 import { getServerTags } from './lib/servertags.js';
 import { UdpEvents } from './lib/udp-event.js';
+import { verifyConfigFileSchema, verifyAppConfig } from './lib/config-file-verify.js';
 
 let instance = null;
 
@@ -134,6 +135,7 @@ class Settings {
                 process.exit(1);
             }
         } else {
+            // No config file specified on command line.
             // Get value of env variable NODE_ENV
             const env = process.env.NODE_ENV;
 
@@ -143,8 +145,39 @@ class Settings {
             this.configFile = upath.resolve(dirname, `./config/${env}.yaml`);
         }
 
+        // Full path to config file in this.configFile
+        // Verify schema of config file
+        // Only do this if the command line option no-config-file-verify is NOT set
+        if (this.options.skipConfigVerification) {
+            console.warn('MAIN: Skipping config file verification');
+        } else {
+            let configFileVerify = await verifyConfigFileSchema(this.configFile);
+
+            // If config file verification failed, the previous function would have returned false.
+            // In that case, we should exit the script.
+            if (!configFileVerify) {
+                console.error('MAIN: Config file verification failed. Exiting.');
+                process.exit(1);
+            }
+        }
+
+        // Load config file
         this.config = (await import('config')).default;
 
+        // Verify application specific settings and relationships between settings
+        if (this.options.skipConfigVerification) {
+            console.warn('MAIN: Skipping application specific config verification');
+        } else {
+            let appConfigVerify = await verifyAppConfig(this.config);
+
+            // If application specific config verification failed, the previous function would have returned false.
+            // In that case, we should exit the script.
+            if (!appConfigVerify) {
+                console.error('MAIN: Application specific config verification failed. Exiting.');
+                process.exit(1);
+            }
+        }
+
         this.execPath = this.isPkg ? upath.dirname(process.execPath) : process.cwd();
 
         // Are we running as standalone app or not?
diff --git a/src/lib/config-file-schema.js b/src/lib/config-file-schema.js
index 2ab15573..626a00f9 100755
--- a/src/lib/config-file-schema.js
+++ b/src/lib/config-file-schema.js
@@ -7,7 +7,7 @@ export const confifgFileSchema = {
                 logLevel: {
                     type: 'string',
                     enum: ['error', 'warn', 'info', 'verbose', 'debug', 'silly'],
-                    transform: ['trim', 'toLowerCase'],
+                    transform: ['trim'],
                 },
                 fileLogging: { type: 'boolean' },
                 logDirectory: { type: 'string' },
diff --git a/src/lib/config-file-verify.js b/src/lib/config-file-verify.js
index ad2b9469..f84df94e 100755
--- a/src/lib/config-file-verify.js
+++ b/src/lib/config-file-verify.js
@@ -2,12 +2,11 @@ import { load } from 'js-yaml';
 import fs from 'fs/promises';
 import { default as Ajv } from 'ajv';
 
-import globals from '../globals.js';
 import { confifgFileSchema } from './config-file-schema.js';
 
 // Function to verify that the config file has the correct format
 // Use yaml-validator to validate the config file
-export async function verifyConfigFile() {
+export async function verifyConfigFileSchema(configFile) {
     try {
         const ajv = new Ajv({
             strict: true,
@@ -27,8 +26,8 @@ export async function verifyConfigFile() {
         // Add formats to ajv instance
         ajvFormats.default(ajv);
 
-        // Load the YAML schema file, identified by globals.configFile, from file
-        const fileContent = await fs.readFile(globals.configFile, 'utf8');
+        // Load the YAML schema file, identified by configFile, from file
+        const fileContent = await fs.readFile(configFile, 'utf8');
 
         // Parse the YAML file
         let parsedFileContent;
@@ -52,87 +51,83 @@ export async function verifyConfigFile() {
             // - message: The error message
 
             for (const error of validate.errors) {
-                globals.logger.error(
-                    `VERIFY CONFIG FILE: ${error.instancePath} : ${error.message}`
-                );
+                console.error(`VERIFY CONFIG FILE ERROR: ${error.instancePath} : ${error.message}`);
             }
 
             process.exit(1);
         }
 
-        // ------------------------------
-        // Verify values of specific config entries
-
-        // If InfluxDB is enabled, check if the version is valid
-        // Valid values: 1 and 2
-        if (globals.config.get('Butler-SOS.influxdbConfig.enable') === true) {
-            const influxdbVersion = globals.config.get('Butler-SOS.influxdbConfig.version');
-            if (influxdbVersion !== 1 && influxdbVersion !== 2) {
-                globals.logger.error(
-                    `VERIFY CONFIG FILE: Butler-SOS.influxdbConfig.enable (=InfluxDB version) ${influxdbVersion} is invalid. Exiting.`
-                );
-                process.exit(1);
-            }
-        }
+        console.info(
+            `VERIFY CONFIG FILE: Your config file at ${configFile} is correctly formatted, good work!`
+        );
 
-        // Verify that server tags are correctly defined
-        // In the config file section `Butler-SOS.serversToMonitor.serverTagsDefinition` it's possible to define zero or more tags that can be set for each server that is to be monitored.
-        // When Butler SOS is started, do the following checks:
-        // 1. All tags present in `Butler-SOS.serversToMonitor.serverTagsDefinition` must be set for each server in `SOS.serversToMonitor.servers[]`
-        // 2. The tags specified for each server in `SOS.serversToMonitor.servers[].serverTags` must be present in `Butler-SOS.serversToMonitor.serverTagsDefinition`
-        // If either of the conditions above is false, an error should be logged and Butler SOS should not start.
-        try {
-            // Loop over all defined server tags
-            const serverTagsDefinition = globals.config.get(
-                'Butler-SOS.serversToMonitor.serverTagsDefinition'
+        return true;
+    } catch (err) {
+        console.error(`VERIFY CONFIG FILE: ${err}`);
+
+        return false;
+    }
+}
+
+// Function to do verification of app specific settings and relationships between settings
+export async function verifyAppConfig(cfg) {
+    // Verify values of specific config entries
+
+    // If InfluxDB is enabled, check if the version is valid
+    // Valid values: 1 and 2
+    if (cfg.get('Butler-SOS.influxdbConfig.enable') === true) {
+        const influxdbVersion = cfg.get('Butler-SOS.influxdbConfig.version');
+        if (influxdbVersion !== 1 && influxdbVersion !== 2) {
+            console.error(
+                `VERIFY CONFIG FILE ERROR: Butler-SOS.influxdbConfig.enable (=InfluxDB version) ${influxdbVersion} is invalid. Exiting.`
             );
-            for (const tag of serverTagsDefinition) {
-                // Check that all servers have this tag
-                const servers = globals.config.get('Butler-SOS.serversToMonitor.servers');
-                for (const server of servers) {
-                    // Check if server.serverTags.tag is defined
-                    if (server?.serverTags === null || !server?.serverTags[tag]) {
-                        globals.logger.error(
-                            `VERIFY CONFIG FILE: Server tag "${tag}" is not defined for server "${server.serverName}". Exiting.`
-                        );
-                        process.exit(1);
-                    } else {
-                        globals.logger.verbose(
-                            `VERIFY CONFIG FILE: Server tag "${tag}" is defined for server "${server.serverName}".`
-                        );
-                    }
-                }
-            }
+            return false;
+        }
+    }
 
-            // Now ensure that the tags defined for each server are valid and that there are no extra tags there
-            const servers = globals.config.get('Butler-SOS.serversToMonitor.servers');
+    // Verify that server tags are correctly defined
+    // In the config file section `Butler-SOS.serversToMonitor.serverTagsDefinition` it's possible to define zero or more tags that can be set for each server that is to be monitored.
+    // When Butler SOS is started, do the following checks:
+    // 1. All tags present in `Butler-SOS.serversToMonitor.serverTagsDefinition` must be set for each server in `SOS.serversToMonitor.servers[]`
+    // 2. The tags specified for each server in `SOS.serversToMonitor.servers[].serverTags` must be present in `Butler-SOS.serversToMonitor.serverTagsDefinition`
+    // If either of the conditions above is false, an error should be logged and Butler SOS should not start.
+    try {
+        // Loop over all defined server tags
+        const serverTagsDefinition = cfg.get('Butler-SOS.serversToMonitor.serverTagsDefinition');
+        for (const tag of serverTagsDefinition) {
+            // Check that all servers have this tag
+            const servers = cfg.get('Butler-SOS.serversToMonitor.servers');
             for (const server of servers) {
-                for (const tag in server.serverTags) {
-                    if (!serverTagsDefinition.includes(tag)) {
-                        globals.logger.error(
-                            `VERIFY CONFIG FILE: Server tag "${tag}" for server "${server.serverName}" is not defined in Butler-SOS.serversToMonitor.serverTagsDefinition. Exiting.`
-                        );
-                        process.exit(1);
-                    } else {
-                        globals.logger.verbose(
-                            `VERIFY CONFIG FILE: Server tag "${tag}" is defined in Butler-SOS.serversToMonitor.serverTagsDefinition.`
-                        );
-                    }
+                // Check if server.serverTags.tag is defined
+                if (server?.serverTags === null || !server?.serverTags[tag]) {
+                    console.error(
+                        `VERIFY CONFIG FILE: Server tag "${tag}" is not defined for server "${server.serverName}". Exiting.`
+                    );
+                    return false;
+                } else {
+                    // The tag is defined for this server
                 }
             }
-        } catch (err) {
-            globals.logger.error(`VERIFY CONFIG FILE: Server tags verification failed. ${err}`);
-            process.exit(1);
         }
 
-        globals.logger.info(
-            `VERIFY CONFIG FILE: Your config file at ${globals.configFile} is valid, good work!`
-        );
+        // Now ensure that the tags defined for each server are valid and that there are no extra tags there
+        const servers = cfg.get('Butler-SOS.serversToMonitor.servers');
+        for (const server of servers) {
+            for (const tag in server.serverTags) {
+                if (!serverTagsDefinition.includes(tag)) {
+                    console.error(
+                        `VERIFY CONFIG FILE: Server tag "${tag}" for server "${server.serverName}" is not defined in Butler-SOS.serversToMonitor.serverTagsDefinition. Exiting.`
+                    );
+                    return false;
+                } else {
+                    // The tag is defined in Butler-SOS.serversToMonitor.serverTagsDefinition
+                }
+            }
+        }
 
         return true;
     } catch (err) {
-        globals.logger.error(`VERIFY CONFIG FILE: ${err}`);
-
+        console.error(`VERIFY CONFIG FILE: Server tags verification failed. ${err}`);
         return false;
     }
 }