I'm experiencing a similar issue to one of the problems you're describing: an empty Home tab that fails to load and black interface behind the page. For me it happens in the OnlyOffice "Document" integration. (see screenshots below)
I found another post from 2025 of a user with the same issue:
https://forum.cryptpad.org/d/2521-onlyoffice-document-home-tab-missing-options
I had this issue two days ago as well, it went away, and now it's back..
I tried to find out if anything in my setup caused the issue. I did a lot of testing with changing setups removing site data and refreshing or opening other documents. The bug seems to be inconsistent in behaviour. I didn't find a pattern or a fix.. It obviously has something to do with the loading of the OnlyOffice elements and possibly with some cached site data it uses for that purpose.. But that's as far as I get.
These are the things I tried:
Setup:
I'm using Firefox.
I tried turning off all extensions - no change in behaviour.
Running in a new incognito mode session with extensions turned off has the same behaviour: first load loads the Home toolbar and interface background properly, refreshing the page breaks it..
Tried a different (completely unused) browser: Microsoft Edge same behaviour.
The issue happens in both light mode and in dark mode.
Removing site data and reopening the document solves the issue temporarily but simply reloading the tab or opening the document or a different document in a new tab will break the interface again.
So after removing site data you can only open a document once before this bug happens again.
-- And then, during my testing suddenly the bug stopped happening...
But it returned: after opening three or four different documents the bug showed up again. With a change in behaviour however: Before I could only open one document properly after a site data removal, all subsequent opened documents or a refresh were broken. But this time it didn't happen some other documents even after refreshing.. Refreshing the broken document still broke the interface there. But refreshing or opening others didn't replicate the issue right away..
However, soon the issue turned up with some of those instances as well.
It became really inconsistent.
Refreshing multiple times during loading of the page seems to sometimes reset it again, removing the issue temporarily and making it load everything properly...
I suspected it had something to do with whether headings were used in the document since a document without headings didn't seem to break the interface after multiple refreshes.. But then after a while that document glitched as well.. Although the multiple refresh trick did seem to force it to load properly later on...
So now it's really inconsistent.. Multiple refreshes before the page fully loads seem to have an effect to resetting the interface back to loading normally, but whether that's really doing anything rather than some unrelated timing based issue on the backend is not clear. And if refreshing halfway indeed affects the bug from happening it's unclear at what point during the loading process you should refresh for it to work...
I'm at a loss to what can cause this issue.. Somehow, once the OnlyOffice integration initialises it stores (or fails to store) something in site data as some sort of cache that it relies on to load certain interface elements, which it then fails to do when loading the same or another document again... However, in some cases it loads everything just fine while the bug persists in another tab..
Here are some screenshots:
Correctly loaded interface (right after a reset - everything loads proprerly, grey background)
Glitched interface Home tab failed to load properly, background behind document page is black.
