Error: ENOENT: no such file or directory, open

[leisegang]

2018-01-25 17:42:54 [pool] (Thread 1) Started server listening on port 3333
2018-01-25 17:42:54 [master] Pool fork 1 died, spawning replacement worker...
2018-01-25 17:42:56 [pool] (Thread 1) Blockchain height changed to 0, updating template.
2018-01-25 17:42:57 [pool] (Thread 1) Blockchain height changed to 0, updating template.
2018-01-25 17:42:58 [pool] (Thread 1) New block to mine at height 95019 w/ difficulty of 9204966698

Error: ENOENT: no such file or directory, open ''
at Error (native)
at Object.fs.openSync (fs.js:549:18)
at Object.fs.readFileSync (fs.js:397:15)
at /home/patrick/pool/lib/pool.js:809:21
at /home/patrick/pool/node_modules/async/lib/async.js:181:20
at Object.async.forEachOf.async.eachOf (/home/patrick/pool/node_modules/async/lib/async.js:233:13)
at Object.async.forEach.async.each (/home/patrick/pool/node_modules/async/lib/async.js:209:22)
at startPoolServerTcp (/home/patrick/pool/lib/pool.js:714:11)
at jobRefreshCompleteCallback (/home/patrick/pool/lib/pool.js:263:9)
at /home/patrick/pool/lib/pool.js:232:17

screenshot:
https://www.leisegang.no/src/-lNd5aSi.png
https://www.leisegang.no/src/Pwc9KIy_.png