Using a Pro 2015 license on a Mac and PC, having problems

I was thrilled to read that Sketchup Pro 2015 works on both Mac and PC under the same license. However the serial number I was given is not recognized by my Mac desktop. The technical support link given on the license email does not work either. I have successfully used the program on my PC laptop and will gratefully accept advice.
Thanks for your time.

does work with SU v2015 only (serial starts with ‘Q’), older licencse are not cross-platform.

if you have downloaded and installed the recent version this could be a typo only. Do a copy & paste from your license email and ensure, that there is no space before and behind the serial no.

you system needs to be online doing that.

Thanks for your time.

I do have the 2015 Pro version and it’s working smoothly again. Now I just have to practise, practise, practise.

Chelsea dawn