.zip files are not processed correctly

When uploading a zipped map (CellDesigner) I get the following error: Failure: Problem with uploading map: Content is not allowed in prolog.. More details can be found in log file.

When uploading a zipped map (SBML) I get the following error: Failure: Problem with uploading map: com.ctc.wstx.exc.WstxIOException: Invalid UTF-8 start byte 0xa1 (at char #63 (closed), byte #-1). More details can be found in log file.