Recurring problem with PDF Passwords across multiple docs and users

[Liz5F96]

Hi,

We are having an issue were recently several members of our team are finding themselves unable to open password protected pdfs, constantly getting the "wrong password, check caps lock" error, even when we know they are using the correct password (and don't have caps lock on). 

This is impacting at least 3 team members, 2 of which are using reader, 1 who has acrobat pro. 

It's occuring across multiple documents, which have all been created by external parties, not the users themselves.

Other memebers of our team have been able to open these same documents using the same passwords without issue.

I have watched the impacted users trying to open the docs, both by manually typing in the password and by copy-pasting, and they don't appear to be doing anything differently to the users who can open the docs. 

Everyone has the same security settings as far as I'm aware.

Any ideas what might be going on here and how we can resolve? 

TIA!

[try67]

What's the exact version number of the application they're using (You can find it out by going to Help - About Adobe Acrobat)? What's their OS version? How were the files created? Can you share a sample file?