Just thought I'd add to this - we are getting the same error on a windows environment.
We've opened security on the c:\programdata folder for everyone, full. And this works for a day.
next day PS errors immediately and closes. Resetting the program data fixes the issue for a day.
on further investigation, the permissions on the pslog.txt file, in the root of program data is only read, read & execute - despite the folder having everyone full. resetting this permission fixes the issue - for a day.
I am assuming PS is generating this each day, with the time stamp in it - but it looks like the wrong permissions are being set.
Any ideas?