Calendar doesn't load after upgrade to 10

I upgraded my Nextcloud installation from version 9.0.53 to 10 today. The upgrade process itself was really smooth and reported no errors. After the upgrade was finished, I disabled the maintenance app and enabled the apps again that were disabled during the upgrade process (spreedme, ojsxc, calendar, contacts, tasks, documents). Most of them work however the calendar app just doesn’t load any more. The left bar which allows to select the different views (Day, Week, Month) is still there but the rest is a completely blank page.

The calendar app was updated to 1.3.3 during the Nextcloud upgrade so it should be compatbile with the release. Just to be sure I also uninstalled the calendar app and reinstalled it through the admin interface.

The Chromium inspector shows that all files that are requested when the calendar app is loaded are loaded successfully, no 404s or other errors. However the Javascript console reports an angular.js error about a failure to instatiate ngRoute. I have uploaded the full log here:

https://owncloud.helmut-pozimski.de/index.php/s/Kpj7MGZzH4qxXua

My environment is Debian 8 with php 5.6.24 and apache 2.4.10. The Nextcloud log in data shows no errors. I have tried so far with Chromium 52 and Firefox-ESR 45.

Did you have asset-pipeline enabled? This feature was removed and there are perhaps problems with caching. Did you try to clear your cache and reload the page (or try a different browser/system).

I never used that feature, didn’t even know about it’s existence until you mentioned it. I explicitely disabled it in the configuration just to be sure but it didn’t make the calendar work. However this brought me to investigate the angular.js-Issue further. Some threads mentioned that “angular-route.js” was needed for “ngRoute” to work. This file is not included in the current version of the calendar app and also isn’t requested in the HTML/PHP code.

grep then helped me to find all files that included “ngRoute” and I indeed found the angular-route.js in an unexepected place: The directory “calendar” in the nextcloud root directory. This one still contained the outdated version 1.3.1. I just know that I didn’t create the directory there myself and also didn’t copy it there. I can just assume that this was supposed to be a backup of the previously installed 3rd-party apps that was created by occ during the upgrade process since copies of all other 3rd-party apps were there as well.

So I ended up deleting these backup directories and that solved the issue. The calendar loads again and everything else works too. Probably I could have found this out earlier since the integrity check complained about all the unexpected files in the root directory but I didn’t pay enough attention to these errors.