Just dropping-in to share that, one year on, this is still an issue with RFSB's LICC scenery.
Also that @fluffyflops fix (install another SimMarket scenery first) is still the right one (thank you!). I would add though that I think the scenery you install first needs to be one that uses the same type of installer as the LICC scenery. In my case, I installed a UK2000 scenery (from SimMarket) before LICC, and this didn't help. It was only after I installed LIPZ, also by RFSB, that the LICC installation worked.
SimMarket support seemingly remain unaware of the issue ("We are 100% sure something is wrong on your side...") and took me down a whole rabbit hole of making unnecessary, and increasingly risky system changes before I found the answer here!
