I too am seeing this crashing when using WSJT-X V2.5.3 (Win 10, 64-bit) with certain portable calls. Using along side HRD for rig control and logging.
I can't get it to happen every time, but it's only been with /stroke calls.
Upgraded to 2.5.3 yesterday and noticed the first crash in QSO with several Japanese FT8 stations.

Each time, I'm replying to a CQ call or a blind call from another station mid-QSO. I am double clicking on the RXFrequency decode window to grab their call and auto gen messages.
Not sure if it matters, but I'm using split with the "Hold TX Freq" option to send. Also using Deep Decoding.

The process for "jt9 - WSJT-X slow mode decoder" must be manually killed to be able to re-launch WSJT-X.

Radio: Kenwood TS-2000 w/Signalink USB interface.

Win10 Event Viewer App Error record:
Faulting application name: wsjtx.exe, version: 2.5.3.0, time stamp: 0x61b0e1e7
Faulting module name: ntdll.dll, version: 10.0.19041.1288, time stamp: 0xa280d1d6
Exception code: 0xc0000374
Fault offset: 0x00000000000ff199
Faulting process id: 0x8b4
Faulting application start time: 0x01d7f1fd6c5bf4f2
Faulting application path: C:\WSJT\wsjtx\bin\wsjtx.exe
Faulting module path: C:\WINDOWS\SYSTEM32\ntdll.dll
Report Id: c7cb1266-3a41-46df-98f1-a78927471446
Faulting package full name:
Faulting package-relative application ID:

Log Name: Application
Source: Application Error
Date: 12/15/2021 2:27:57 PM
Event ID: 1000
Task Category: (100)
Level: Error
Keywords: Classic
User: N/A
Computer: BEAST
Description:
Faulting application name: wsjtx.exe, version: 2.5.3.0, time stamp: 0x61b0e1e7
Faulting module name: ntdll.dll, version: 10.0.19041.1288, time stamp: 0xa280d1d6
Exception code: 0xc0000374
Fault offset: 0x00000000000ff199
Faulting process id: 0x8b4
Faulting application start time: 0x01d7f1fd6c5bf4f2
Faulting application path: C:\WSJT\wsjtx\bin\wsjtx.exe
Faulting module path: C:\WINDOWS\SYSTEM32\ntdll.dll
Report Id: c7cb1266-3a41-46df-98f1-a78927471446
Faulting package full name:
Faulting package-relative application ID:
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Application Error" />
<EventID Qualifiers="0">1000</EventID>
<Version>0</Version>
<Level>2</Level>
<Task>100</Task>
<Opcode>0</Opcode>
<Keywords>0x80000000000000</Keywords>
<TimeCreated SystemTime="2021-12-15T22:27:57.6028305Z" />
<EventRecordID>31293</EventRecordID>
<Correlation />
<Execution ProcessID="0" ThreadID="0" />
<Channel>Application</Channel>
<Computer>BEAST</Computer>
<Security />
</System>
<EventData>
<Data>wsjtx.exe</Data>
<Data>2.5.3.0</Data>
<Data>61b0e1e7</Data>
<Data>ntdll.dll</Data>
<Data>10.0.19041.1288</Data>
<Data>a280d1d6</Data>
<Data>c0000374</Data>
<Data>00000000000ff199</Data>
<Data>8b4</Data>
<Data>01d7f1fd6c5bf4f2</Data>
<Data>C:\WSJT\wsjtx\bin\wsjtx.exe</Data>
<Data>C:\WINDOWS\SYSTEM32\ntdll.dll</Data>
<Data>c7cb1266-3a41-46df-98f1-a78927471446</Data>
<Data>
</Data>
<Data>
</Data>
</EventData>
</Event>



73
Bryan Lynch
NM7C