Adobe Acrobat Pro XI 0 Error when adding "tags"

[mgc3417]

When adding tags to a pdf document for accessibility I get the following error:
message: Bad PDF; error in processing fonts. <unsupported Type2 font>

The clincher is that on another machine with the same Adobe Acrobat version (Pro XI) I do not get the error.  Is there a setting I should know about?   I have compared the settings and I don't see a difference but perhaps something I have missed.

[Test Screen Name · Accepted solution]

You say it's the same version but have you checked? 11.0.20 is the latest bug fix update.

[mgc3417]

Thank you, that worked.   Note to self "always check for updates".