In a free version a problem occurrs when homepage_info_multiloc in app configurations table is set to any value. So if one provides a value in Homepage customizable section like here:
After a reboot editing stops. Steps to reproduce:
Deploy the application as described in the deployment guide (having it with default settings).
Run the application as described in the deployment guide.
Go to Admin Panel -> Settings -> General and make sure that default laguage was set (EN for this case).
Go to Admin Panel -> Settings -> Customize and apply a value for 'Homepage customizable section'
Reboot.
Go to Admin Panel -> Settings -> General
Now editing leads to a 500 Internal Server Error
Connect to DB and execute: UPDATE app_configurations SET homepage_info_multiloc = null
Navigate to Admin Panel -> Settings editing starts working again without any reboot.
Navigate to Admin Panel -> Settings -> General and try setting a value for 'Homepage customizable section' form.
Saving leads to a 500 Internal Server Error
Refresh the page, navigate to Home page and then navigate back to Admin Panel -> Settings -> Customize and try to change anything except 'Homepage customizable section'.
Admin Panel -> Settings editing works.
Adding Projects, Activities, Comments, etc. and editing them does not work.
Reboot.
Adding Projects, Activities, Comments, etc. starts working again.