Acrobat Pro DC closes if not an administrator. How do I fix this for non-admin users?

Hi,

I have installed and entered the serial number for Adobe Acrobat Pro DC. If I start it as an administrator (local or domain) it runs an operates correctly.  If a non-admin users logs on and starts it then it opens, responds but then closes after approx 30 seconds.  I have updated to the latest version, attempted uninstall and reinstall twice.  None of these fix it.

How do I make it work for non-admin users?  Non-admin users cannot click the Sign-In link in the top right as it closes before any sign-in attempt can be made.

It is not an option to give the user administrative permissions, or to use "Run as Administrator" as non-admin users cannot be given administrative permissions or passwords.

Many thanks.