Domino terminated abnormally

I migrated R.5.09a to R6.5.5 FP1 and received a popup with the following text.Domino terminated abnormally. You can restart immediately after clicking ok

one time pear day

This is a bug or I have any problem

Subject: Domino terminated abnormally

hi

You should a file in the IBM_TECHNICAL_SUPPORT named NSD_DateOfTheDay.

Open it and search for the FATAL THREAD section and post it here,

JYR