"Save As" problem

Could someone advice me on how to save back as ver.x1 from an updated ver.x4 library. There is a compatibility issue that I can solve. I am unable to retrive neither to re-save to the previous version.

Are you still able to access/view the library references in X4?  If so, may try exporting the references as a text file using the “Tab Delimited” output style. The resulting text file should then be importable into X2.  But also be sure to make backup copies of the EndNote X4  library files (.enl) and corresponding .data folders just as a safety precaution.

I was under the impression that the libraries should be backward compatible.  --I would contact tech support. The library may have been corrupted?