Unable to add Metadata to an existing PDF - Adobe Pro Stuck on Importing File to Append

Hi There,

I'm trying to help and end user append meta data to an existing PDF for accessibility. When trying to import the metadata through: File >> Properties >> Additional Metadata >> Advanced >> Append.  Then picking the file, I get the following error message:

"You Don't have Permission to Open This File. Contact The File Owner or an Administrator to Obtain Permission"  Screen Shot attached also.

So far I've done the following with no luck:

- put the file in various folders inside and outside of the user profile (c:\temp)
- made sure the user had all file permissions to the file and folders (Full Control, Modify etc)

- made user the owner of the file.

- copy & pasted the contents of the file to a new file and repeat above steps.

- installed latest version of Adobe Pro on separate PC and run as Administrator

- made sure to 'unblock' this file by right clicking, checking the property page

- made sure encryption option was not checked on the file

Verified I could open & save PDF documents to the folders named about without issue.

Seems like its only this meta-data diaglogue box that's having the issue. Like it's some kind of sub-program that's not seeing the same permissions as the main PDF editor.

Any ideas? Doesn't seem like a Windows thing to me at this point...

Thanks,