Not sure if it's gonna be any help, I just came across this issue today as well.
I use a mac. I think the first step is to make sure all 3 green ticks are on in your License Administrator.
If installing a new license and manually installing a license are greyed out, it most likely means you don't have write permission to change the license.local files. Make sure you check your permissions on the machine. I encountered this on my windows boot camp.
I'm not sure how it was determined on installation, but my license admin was set to network licensing, when in fact it should be local licensing, this relates to the tick that says "This server is unable to dish out licenses". So you need to go to your license.local and change the license variable to local licensing.
https://www.sidefx.com/faq/apprentice-local-licensing/#faq73
Took me some time to figure it out, hope it helps!