I am using Nextcloud for several years now without any issues but with update to Nextcloud 30 a few issues were introduced:
Most importantly file sharing via mail link is broken, bug was listed but no workaround or fix is known for now.
Also: Installing Enabling Apps via web client is broken if you are behind a reverse proxy. Workaround is to use the occ cli client to install, enable/disable addons.
And: RuntimeException image not found: image:apps/whiteboard.svg error that quickly fills your log if you do not have the whiteboard app installed. Workaround is to install the app.
Anyone else with similar experience since NC30? It seems to me that NC30 release was not very well tested?
I don’t use the share via email function so I can’t tell if that’s working or not. But I haven’t seen the other issues you mentioned. I can install/update apps fine in the web-interface and I haven’t seen any errors regarding whiteboard.