This is one of those weird kinds of errors the main thing to check for would be a misreferenced file in say a ResearchPreRequisite for example you must enter:
RESEARCH_SUBJECT_FILE
NOT:
RESEARCH_SUBJECT_FILE.entity
There are many situations where this can occur the research one is just the one that pops in to my head right now, best thing to do is make sure that all the files are referenced properly within the other files. Looking up the file may not be the issue. Use the Dev.exe launch it and see if tells you which file is mis-referencing.
Without any more information on what you're doing thats about as much help as I can offer
In this particular instance, it actually is a research subject that has the problem. I created a new starbase for a new player race, and I created a new entity for the trade port starbase research: RESEARCHSUBJECT_STARBASEUPGRADEACCESS_TRADEPORTOVERLORD.entity
I checked all of the files that reference this entity, and they all appear to be formatted correctly. I did use the Dev.exe, and it says "Entity Ref not found: RESEARCHSUBJECT_STARBASEUPGRADEACCESS_TRADEPORTOVERLORD". Then the Dev.exe minidumps and crashes.
Let me know if there is any other information that would help...