This is not a PAM Client error. Please visit the following link for a description and cause of this problem:
Error “Cannot Open System Clipboard”, trying to set system clipboard fails/works on and off. What is the cause?
So, this should not be specific to PAM Client but can occur between other software whatever takes over the clipboard.
When another software has taken ownership of the clipboard, other applications can return that error while accessing the clipboard if the initial application does not release the clipboard ownership.