2.6 to 2.8 CAS_sso problem

Hi all

I am attempting to upgrade my 2.6 version to 2.8 on anew server and get it running under Git updates. One major reason for the change of server is that the OS on the old one does not support the latest version of MySQL.

Anyway I am nearly there, have been copying in our added modules/plugins etc to the new 2.8 setup. However I am stuck on one. Right at the bottom of the list of plugins checked I have the heading 'Local Pluigins' and listed as missing from the disk is CAS-sso. If i tell the process to continue I get the following message and I am unsure where to go from here? Any help appreciated.

Cheers

Simon