I just installed CE 2015 and attempted to download some project data.
The example projects that I was trying to download are those included in the tutorials at CityEngine Tutorials. The two that I attempted were Exercise 1 and 9. I attempted the import zipped project option and received the attached error on both. The reason for attempting with both is that one is tagged 2014.0,2014.1,2015.0 and the other is only tagged for 2015.0. Also (although it is not the advised method, I wanted to exhaust all attempts) I unzipped the project in my \\C: using extract all and attempted to import that project, I got and identical error. This is the same error that Im getting when I try to migrate my 2014.1 data to 2015.0. Is anyone else having this issue? Did you find a fix or a work around? If not any ideas of what the root cause may be?