I have a pretty big model that I am having issue with when I go to update it. I get the dreaded "geometry not available" error. I believe I have found out the reason that I get this and would like to know if it is a bug and has been fixed in version 6 (have the new version but our IS dept has not loaded yet and will not give a date when). Anyway here is what is happening. I have a big project that I have been working on and 90 percent of it was done in MDT6. I started doing a small section in inventor and I just linked the MDT file in (I did not convert the drawings because there are a lot of models and drawings). It seems that every constraint that is constrained to the main MDT6 file says geometry not available when it is opened at a later date. Has anyone else had any issues with using MDT6 parts in inventor? Thanks in advance Jon