possible problem xml:lang item

After running access-aide on an old epub file, epubcheck gives the following error for a line in the opf file.
Col: 105: ERROR(RSC-005): Error while parsing file: attribute ""xml:lang"" not allowed here; expected attribute ""id""

The Package version shows 2.0, so I thought this might be a version issue.
I tried the latest version of epub3-itizer. The conversion went OK, but the package still shows 2.0 and epubcheck gave the same error.

Any suggestions for where to look for the cause of this problem and fix it?

Thanks,
Jim