Hello. I have the same problem:
www.flexiblewebdesign.com/forum-joomla-virtuemart-template-coolmart-support/2190-problem-to-save#9994
I tried to clean cache, temporary files but i got same error. I tried to use IE, Firefox, Chrome, Opera browsers but nothing. How i can save licence key?

Normally, changing the browser should have worked just fine.
(if the problem occurs on Chrome, opening the Firefox and trying again should have worked just fine. Or the other way around)

Probably there is a permission problem in your case (CHMOD)

There is a manual method to save the template settings. Open this file below with a Text Editor (Notepad, TextEdit, Dreamweaver etc..):

/templates/flexible_asymmetric/config
(It is not a folder, it is a file without any extension)

and look at the 1st and 2nd declarations, you will see this:

type your username and order number manually between quotations.
For example, like this:
and save the file.

FYI: when you clicki the SAVE button in the Joomla Backend >> Template Manager, your Joomla actually tries to do the same thing. Saving your changes to that file. But having a not-write-access for that config file might also cause a problem. I am guessing you are having the permission problem since changing browser didn't work for you)

Regards,
Support

Thanks. Problem solved

Sure, your welcome.

Case solved. Topic is closed.

regards.