I cannot Open Flight Plans from Flight List in PPS

If you try to open a Flight from your Schedule flight List or from your CrewBriefing Flight List you can in rare situations be met by this error:

An error occurred while opening flight, probably due to missing data

This could be one of the following reasons:

• Incorrect crew positions in your aircraft file compared to your data exported from your Schedule System.
• Mismatch or incorrect input in your MEL section.