Are you sure the error is happening in GetSequenceFileEx and not somewhere else in your code? If you are using the global version of the type like you've specified and it doesn't contain some properties you are expecting, your code might be trying to access properties that no longer exist. It's better to use ConflictHandler_Error or ConflictHandler_Prompt then ConflictHandler_UseGlobalType. ConflictHandler_UseGlobalType overrides the default conflict resolution behavior.
If you are sure that it's GetSequenceFileEx itself that is directly reporting the error, then please try to create a simple case which reproduces the problem and attach the files to this post. You likely need two files, one with the global version of the type involved and one with the types as they are in your file.
-Doug
