Get all type of file clasfication using metadata

Hi All

We have a requirement to read the file clasification i.e. internal,public,confidential etc. We are usng readofficedoccustomprops function & tried with multiple functions & smart services. But did not find the function/smart service for it to get clasfucation for all file types ( docx,pdf,excel,csv,ppt).

using readofficedoccustomprops function & MS Office Read Custom Metadata plugin , we could able to get the Classification for external type files but when trying with clasification as internal /confidential it is giving error with file metadata.

Can any one faced similar issue to read metadata of all type of files .Please share with us.