Problem: Can't find offset base

 Description:
        The current item has an operand marked as an offset,
        but IDA can't find the offset base in the database.

 Possible reason(s):
        Probably IDA's base is corrupt.
        This may occur if the database was corrupted and repaired.

 What to do:
        Mark the operand again as an offset. Use one of the following
        commands:
         Convert to offset (DS)
         Convert to offset (CS)
         Convert to offset by any segment
         Convert to offset by any user-specified base