Straton processes close unexpectedly

Straton processes close unexpectedly

We use a global project with 7 subprojects. Each subproject has an individual straton process. Sometimes, one time per two or three weeks part of straton processes closes unexpectedly. 

Is it possible to detect the reason for closing processes? Cant find any straton logs in the work folder.

Zenon 8.20.

I appreciate any help. Thanks.