Hi,
Try this: Uninstall PixInsight completely. Make sure all the PixInsight files and folders have been removed. Then reboot the PC.
There are a number of applications that will test the memory (RAM) of the PC. Search Google for PC diagnostics program and test the memory.
Now download the latest version of PixInsight and install as normal. Reboot the PC and post back the results.
Look up
John