Try disabling the option to load history when opening projects. Only save history when it is something you need. Try selecting a subtool and click the make poly mesh 3d button to make a clean clone with no history. Try exporting that as both a tool and obj.
hi I have another problem ... I saved a huge file with a whole model complete with all subdivision levels for all pieces, polypainting , and undo history ... tough the following problems : 1 if I try to decimate an item it freezes Zbrush 2 if I try to save the file Crashes 3 if I try to save the tool crashes 4 if I try to…