Is there a way to abort a single tab/drawing/model

[Anonymous]

With both the top level assmbly and the subassembly open in separate tabs, II did the following

   1) promoted all parts in an subassembly

   2) deleted subassembly from top level assembly

   3) mistakenly clicked on the subassembly tab

Now I am stuck in an endless loop of "Encountered an improper argument" errors.

Is there any way to abort the current tab without losing all the work on the other tabs?

Does anyone have any other suggestions about how to save the work on the other tabs?

Help--Oh yes, inventor 12 in windows XP environment, in case it matters.  Is this error fixed in R13 or is there an update to R12?  This is not the first time I have made this silly mistake.

Thanks for your consideration