I received an email that I “have reached my maximum allowed activations or attempted to exceed your allowed number of activations for your SketchUp Pro license. Trimble allows license holders two installations of SketchUp with their Single-User license. You are receiving this email because you have exceeded the allowed amount.”
My laptop died last month and I had to do a system restore which wiped out my software. It still didn’t work quite right so I purchased a new laptop (I also have it on my office PC). The problem I am having is that SketchUp requires you to remove the license from the computer instead of just uninstalling it. I obviously can’t remove a license from a computer in which the software isn’t even installed on it anymore do to the system restore. What are my options?
It appears to be working on both computers though so maybe the first part of the email (have reached my maximum allow activations) is more accurate than the second part of the email (you are receiving this email because you have exceeded the allowed amount).
EDIT: This is an old topic and things have changed greatly concerning SketchUp licenses.
I think, you would need to re-install SketchUp (of the proper version) on the restored laptop, and re-enter the license. It should license ok.
Then reboot, and remove the license, via the Help > License dialog.
Then install the same version SketchUp on the new laptop.
Lastly, uninstall SketchUp from the restored laptop, once the licensing for the new laptop is successful.
But, exhaust the online Help support first:
I’m having a similar issue to @jodisolito
In my case, however, I believe the second activation that is tying up my license is on a computer which has been dismantled entirely when I replaced my CPU and motherboard in late 2020. @DanRathbun suggestion to reinstall and then deactivate is not an option in this case, since this PC no longer exists.
There must be some path to deactivate a particular license (or do so globally). Perhaps by going through Trimble customer support or something?
Any insights? Perhaps circumstances have changed in the 4 years since this thread was started 
Note that this is an old topic and things have changed greatly concerning SketchUp licenses.
There now is a online license management portal. The link is at the top of this page in the “note box”…
You can get help with your license issues …