Weird. I searched for this specific message with no luck -
Bad request - in handler 'licenses': Splunk.License: failed to add reset from license group:'Enterprise' to active
The regular installation procedure should work: Settings > Licensing > Add license, then browse for the file or paste the file contents in.
Is this what you tried and it didn't work?
The only time I've seen the word "reset" used in Splunk licensing is with a reset license when you go over license too many times in one month.
Are you sure the license file you are using is the right one?
I always use the method to copy and paste the license file TEXT into the text box, you could try that method too.