PDF Promise Rejection 2.6.0

[dauten]

Images display fine in Universal Viewer but whenever I load a PDF I get the following error:

Unhandled promise rejection SyntaxError: "JSON.parse: unexpected character at line 1 column 1 of the JSON data"
	parse http://146.163.157.78/omeka/plugins/UniversalViewer/views/shared/javascripts/uv/uv.js:4
	load http://146.163.157.78/omeka/plugins/UniversalViewer/views/shared/javascripts/uv/uv.js:3
	g http://146.163.157.78/omeka/plugins/UniversalViewer/views/shared/javascripts/uv/lib/offline.js:17
	F http://146.163.157.78/omeka/plugins/UniversalViewer/views/shared/javascripts/uv/lib/offline.js:17
	k http://146.163.157.78/omeka/plugins/UniversalViewer/views/shared/javascripts/uv/lib/offline.js:17
 offline.js:17:10369
	b http://146.163.157.78/omeka/plugins/UniversalViewer/views/shared/javascripts/uv/lib/offline.js:17
	E http://146.163.157.78/omeka/plugins/UniversalViewer/views/shared/javascripts/uv/lib/offline.js:17
	G http://146.163.157.78/omeka/plugins/UniversalViewer/views/shared/javascripts/uv/lib/offline.js:17
	exports http://146.163.157.78/omeka/plugins/UniversalViewer/views/shared/javascripts/uv/lib/offline.js:16
	<anonymous> http://146.163.157.78/omeka/plugins/UniversalViewer/views/shared/javascripts/uv/lib/offline.js:17
	s http://146.163.157.78/omeka/plugins/UniversalViewer/views/shared/javascripts/uv/lib/offline.js:17
	t http://146.163.157.78/omeka/plugins/UniversalViewer/views/shared/javascripts/uv/lib/offline.js:17

the exif, gd, and imagemagick php plugins are all installed:

pi@digitalinit:/var/www/html/omeka/plugins$ php -m
[PHP Modules]
apcu
calendar
Core
ctype
curl
date
dom
exif
fileinfo
filter
ftp
gd
gettext
hash
iconv
imagick
intl
json
ldap
libxml
mbstring
mysqli
mysqlnd
openssl
pcntl
pcre
PDO
pdo_mysql
Phar
posix
readline
Reflection
session
shmop
SimpleXML
sockets
SPL
standard
sysvmsg
sysvsem
sysvshm
tokenizer
wddx
xml
xmlreader
xmlwriter
xsl
Zend OPcache
zip
zlib

[Zend Modules]
Zend OPcache

Error seems to be in UV javascript but could be a configuration error?

Output of composer install:

root@digitalinit:/var/www/html/omeka/plugins/UniversalViewer# composer install
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
  - Installing asset/uv (3.0.33)
    Downloading: 100%         

  - Installing slowprog/composer-copy-file (0.3.1)
    Downloading: 100%         

Generating autoload files
> SlowProg\CopyFile\ScriptHandler::copy
Copied file(s) from vendor/asset/uv/ to views/shared/javascripts/uv/.