Bugzilla

Thanks! 

Meanwhile v115.4.1 was installed. The crash has not occurred again so far.

Thunderbird symbols for v115.4.1 seem to be missing at symbols.mozilla.org. Checked using symchk and WinDBG.

Symbol downloading for Thunderbird for WinDBG 10.0.18362.1 fails:
```
SYMSRV:  HTTPGET: /download/symbols/mozglue.pdb/C2B4F32354D0B6424C4C44205044422E1/mozglue.pdb
SYMSRV:  HttpQueryInfo: 80190194 - HTTP_STATUS_NOT_FOUND
SYMSRV:  HTTPGET: /download/symbols/mozglue.pdb/C2B4F32354D0B6424C4C44205044422E1/mozglue.pd_
SYMSRV:  HttpQueryInfo: 80190194 - HTTP_STATUS_NOT_FOUND
SYMSRV:  HTTPGET: /download/symbols/mozglue.pdb/C2B4F32354D0B6424C4C44205044422E1/file.ptr
SYMSRV:  HttpQueryInfo: 80190194 - HTTP_STATUS_NOT_FOUND
```
```
SRV*x:\symbols*https://symbols.mozilla.org/thunderbird;SRV*x:\symbols*https://symbols.mozilla.org/firefox;SRV*x:\symbols*https://msdl.microsoft.com/download/symbols
```
I tried Mozilla-build too. It gets stuck somewhere while running the first hg line at "adding file changes" and then removes everything.
```
 ~/source
$ hg clone https://hg.mozilla.org/mozilla-central source/
applying clone bundle from https://hg.cdn.mozilla.net/mozilla-central/[40char].zstd-max.hg
adding changesets
adding manifests
adding file changes
transaction abort!
rollback completed
abort: An existing connection was forcibly closed by the remote host
```
https://developer.thunderbird.net/thunderbird-development/building-thunderbird/windows-build-prerequisites

The processingspeed is 1 kilobyte per second at the end of "adding manifests".  "Adding file changes" stalls at 3460. Until hg aborts after several minutes, cpu core utilization is close to 95%.

I'd need source code, a debug build, and a build environment to be able to trace problems in Visual Studio. Not only here, in bug 1847137 too.

NULL pointer references can be found and prevented:
https://blog.bytehackr.in/understanding-and-preventing-null-pointer-dereference