Created attachment 184396 [details]
drkonqi log

the backtrace narrows down where the crash happens , but not quite enough to find a fix.

is there any chance you could find the incidence in your calendar that's causing the crash and sending that to me (or attaching here)?
you can redact the contents but I do need to see the recurrence info

(In reply to Allen Winter from comment #2)
> the backtrace narrows down where the crash happens , but not quite enough to
> find a fix.
> 
> is there any chance you could find the incidence in your calendar that's
> causing the crash and sending that to me (or attaching here)?
> you can redact the contents but I do need to see the recurrence info

Hello Allen, and thanks for your quick reply. Unfortunately I can't provide anything else, as the program is so unresponsive right at the startup, that I can't do anything within it and it just only possible to come out by killing it. Even If I started it through the terminal, it is so very frozen that even pressing CTRL+C within the terminal can't terminate the process. 

However, I think it's not related to calendar by any means, but instead related to online accounts somehow. For example, I opened the standalone Korganizer and there, I can see my calendar, and that program doesn't freeze out. Same applies to Kmail: it works. KAddressBook also works. 

Only Kontact is freezing out, I guess cause it is a unification for all the above mentioned programs.

FYI there is a seemingly similiar issue, that was created not long ago, like 4months ago: https://bugs.kde.org/show_bug.cgi?id=502578

I launched again Kontact, and now DrKonqi provided another kind of log, its a bit different from the previous, I pressed on "download debug symbols" or something like that, cause it said it can provide better info for bugreporting, and it says it went from 1/3 star bugreport quality to 3/3 -  I attached that now as well, hope it helps somehow..

Created attachment 184399 [details]
another log

Created attachment 184400 [details]
and another log

oh, I may have misread the backtrace

did you try the `export QT_QPA_PLATFORM=xcb` trick?
this maybe the nvidia and wayland interaction problem

(In reply to Allen Winter from comment #6)
> oh, I may have misread the backtrace
> 
> did you try the `export QT_QPA_PLATFORM=xcb` trick?
> this maybe the nvidia and wayland interaction problem

Its okay. I didn't try it, but now I tried it, and it does not work still. I don't think its an nvidia + wayland interaction problem, because as I said when I created a new user profile, this simulating a totally new and fresh /home folder for it, where no akonadi, no .config for the said apps, no .local nor .cache resides - and this way, Kontact could start up as usual. The bug only happens, as I said, after logging into account, that Kontact throws up with the account wizard, at the very first startup. After account is attached, the crash keeps happening on the said freshly made profile aswell, narrowing down the problem to something happening either in the akonadi database, or some rogue bug in the data files. And only happens in kontact, where all the other programs are unified here. 

If I launch the separate applications (korganizer, kmail, kaddressbook etc-etc..) as I mentioned earlier, everything just works as intended.

Also a plus note, of why it can't be Nvidia, (and no offense, but it is starting to get tiresome, that everyone is constantly blaming Nvidia) is that this exact same bug happens on my Mom's HP AMD (!!!) based (both GPU and CPU) is experiencing the same bug. 

Additionally nonetheless, I have a Lenovo T430 aswell, which is pure Intel based, and this bug is present there aswell.

As I said, this bug had risen recently, everything was fine 2-3 months ago. I guess its the new 25.08 upgrades

Any progress?