TestStand persisted data (like a watch window data) could be a reason behind such aborts or stopping of sequence unexpectedly. In my case, I tried to check function AbortAll() in the watch window and ran into an infinite loop of aborts whenever I try to pause the sequence. To add more trouble, it didn’t allow me to delete it as Watch View becomes inaccessible (see greyed out below) after sequence aborts.

To overcome this issue, the Watch expressions are persisted in the TS common app data can be edited in a simple text editor. Open TeststandPersistedOptions.opt found in below path in a notepad and remove the section as highlighted in following screenshot.
C:\ProgramData\National Instruments\TestStand 2021 (32-bit)\Cfg\TeststandPersistedOptions.opt
Ajay is a professional developer and architect of NI-LabVIEW applications with extreme interest in getting the hardware connected to LabVIEW and automating the stuff. Recently he is also putting his hands in NI-TestStand to get very dirty on it. He is also a good mentor for the various interns in his career. He is ready to help the people in techie roles.