Jim, W7CT and I have been duplicating an issue with 2.5.3 (64-bit version if that matters) this morning, where you start to work a portable call and the UI just terminates...a WSJT process is left running, so you can't start another instance of WSJT until you find terminate the process.  We have duplicated this issue trying to work portable callsigns.  Specifically, N6QEK/KL7, HC1MD/2 (12M), AE5KO/6 (20M).  Not that the bands matter.  But these were actual callsigns that caused the crash.  And I was able to duplicate it after a restart with N6QEK/KL7, he certainly is wondering why stations just stop completing the exchange if they are running 2.5.3. :)
Anyone else noticed this with 2.5.3?
This has been duplicated with Windows 10 and Windows 11.  NG7M running Windows 11 (64 bit obviously) and W7CT running 64bit Windows 10.
Max NG7M