As I am working with designer/workbench (even with designer alone) with other team members and working with different forms on different PCs, the following conditions clearly increase the chances of crashes/errors "There is a problem with Adobe Acrobat/Reader...." .
The errors will more likely trigger if:
1. The form is larger
2. Has more form (visual) fragments, nested fragments and script objects
When the form is relatively smaller, with less number of fragments/nested fragments, then it is pretty acceptable, but eventually, the errors will trigger.
The above may have helped to reduce the number of times the error will be triggered, but not 100% sure. The error still occurs several times per day, especially when I open the fragment and the container (main) form, update the fragment (save) and try to preview the main form.
Next step I will remove/clear Acrobat DC, and reinstall it, hopefully this will make a difference.
I will be monitoring when the error will trigger, and try to find the circumstances that will reduce the chances of the error triggering, and I will be posting my observations....
As per my testing today, I was trying to monitor Adobe LC Designer and Workbench using ProcessExplorer Windows Tool, and I noticed that when I am monitoring the process, the error will most likely not trigger at all, unless this was a coincidence.