I have been trying to upgrade from RC 1.4.11 to a newer version of Roundcube for a while, and even though the upgrade succeeds, every view is empty (the emails list, the settings, etc.), so I always end up reverting to 1.4.11. My method of upgrade is to copy the roundcube folder to a new one and run the bin/installto.sh script on the new folder.
My installation comes from iRedMail and has been upgraded successfully from around 1.2.x up to 1.4.11.
I have tried enabling debug in the config file and didn't see anything suspicious that I remember.
I am using a custom theme (I simply changed some CSS classes and compiled my own Elastic), so I also switched back to the bundled Elastic, and it didn't help.
I checked the browser console and there was nothing there (except a message about an unhandled promise, which also appears on 1.4.11 which works).
I am at a loss, can anyone please suggest alternative routes?
I can provide other details as well, please let me know!