This is indeed troublesome. We’ve done some further changes to the latest version, both functionally but also to improve diagnostics.
Can you please do the following, after the next time you receive the error message?
– Enable the Debug menu by selecting File | Options | Debug
– Open an error log by selecting Debug | Open Error Report Snapshot
Follow the instructions there to copy all text and email it to support at axcrypt dot net . This will help us determine the exact cause.