Keeping 2 versions of template

What is the best method for keeping an older version of the same template on a site? I'm currently using University theme v3.15 with JomSocial v4. The newer versions of University theme do not respect the JomSocial "theme designer" settings but this older version does.

I'd like to update my template but keep the older template installed so I can manually assign it to a few pages for a preferred layout. I've also experienced (when testing the newer themes) a few issues regarding an "Error 500" since the later templates are designed for use with Joomla 3.4 or later.

Thank you in advance for your assistance.

Hi,
you have two options:
1) Rename old template (it request some job in database and files changes)
2) Use only new, but keep part responsible for jomsocial from old one

Okay cool, thank you Oscar. I've renamed the old one and have it assigned to a Contact form as the new theme throws and error, but the problem now is something related to the language file i think... what type of changes in the database need to be made? Will they fix the issue regarding strings of text showing as TPL_GK_LANG_LOGIN_POPUP vs Login?

you have to rename also template language file, like always in such cases.

Where do I find this file? And do I change the name of the file itself or do I change a name within the file?

Filename.
You must have two:
language\en-GB\en-GB.tpl_gk_university.ini
language\en-GB\en-GB.tpl_NewThemeName.ini

You are clever boy you will understand now.

Read also: https://www.gavick.com/documentation/jo ... ate-folder

:- ) Thank you Oscar E, very much appreciated. Happy happy happy