I am able to write and send emails, but they don't show up in my sent folder. My address book is intact and viewable.

Does Help > Troubleshoot Mode help?

No, it didn't. I also tried some of the suggestions in other posts about missing emails. I am in the process of exporting my profile (successful) and will import it an another computer not running v115.2 (in progress) so I can access my emails.

Are you using View > Folders > Unified? Is it better with View > Folders > All?

I was using View > Folders > All and I still don't have any emails showing using either. This has really got me baffled. I exported my files to another computer using V102.15.0 and everything shows up.

The pane system did not initialize. We find so far that users have a folder that causing the problem, and the name of the folder will likely be shown in the error console

Check tools > developer > error console for errors (not warnings) about folders or panes. Please post what you find.

Here's what I found:

NS_ERROR_FAILURE: No directory for uri=moz-abmdbdirectory://abook.mab AddrBookManager.jsm:271

Very strange because my address book is accessible and appears to show everything as it should.

115.2.3 is now available at Help > About. Might not resolve your issue, but we'd welcome your feedback.

Didn't help, but I got some interesting messages at tools>developer>error console:

ERROR: Cannot find loader for bootstrap

NS_ERROR_FAILURE: No directory for uri=moz-abmddirectory://abook.mab