Found the issue.
the PHP Ext "GMP" wasnt installed, as soon as i enabled it, i was able to upgrade.

I run Live Map v2.7.1 on an IIS Server, runs fine but thought i would upgrade it to the latest. When i try and install version 3.0 or 3.12 i click OK and nothing happens. im using the latest TTMod 1.5. Tried on IE/Chrome and Firefox, same result.. any ideas? i dont want to starts a new DB if possibl...