PDF not generating

Hello, great app by the way!

PDF works fine on xampp (localhost), but when transfered to a live domain I can’t generate PDF (both invoice and quote). I am using modified pdf template but it’s not working with the original either.
Everything else works fine and with no errors.

in error log I have few:
Could not find the language line "myline"
and i did add the lines to my lang file:
‘quote_custom_myline’ => ‘myline’,

Also, my htaccess file looks like this (invoiceplane is in sub-folder):

RewriteEngine On
RewriteBase /app
RewriteRule ^index.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

Remove the hash in front of the following two lines if you want to force HTTPS

#RewriteCond %{HTTPS} off
#RewriteRule ^(.*)$ https://%{HTTP_HOST}/$1 [R=301,L]

Thank you very much for any support you folks can provide.