Error when importing GPO into SCM

I have backed up a gpo from our AD DS. When I import it into SCM I receive this error:

The output char buffer is too small to contain the decoded characters, encoding 'Unicode (UTF-8)' fallback 'System.Text.DecoderReplacementFallback'.
Parameter name: chars

I can press OK on a button and then SCM reports that GPO was successfully imported, but when I open the imported GPO, not all settings are there.

Any suggestions for a solution would be appreciated.

Regards,
Klaus