If you find some purple or pink textures at your default airports, check your addon airports as they might cause texture problems at the default airports.
That was the case of MMZH payware over LFPG, LOWI, (identified but it might be more).
I had the same issue, and a bit annoyed as i had reported it both to Sim Market (who then closed my ticket) and the Dev.
To be fair to the dev he suppiied another version the next day, but sadly this too failed to fix the issue. He promised he would redo the textures and have a fix last weekend… still waiting.
With me it was causing purple textures on the Asobo Dusseldorf Airfield, removed MMZH and all was ok