regards!. I have Windows 10, I made the update of the new version, and now the icons of old projects appear white and not opened with a clip, so I can run the old project, first open the program and then select open and is working well. also I have a Mac this all is well only in windows 10 is that problem, please help me.
I would suggest uninstalling and reinstalling After Effects CC 2015.3
It sounds like Windows just didn't associate the files properly.
You can try right-clicking on one of the project files and choosing Open With... and telling it to open with After Effects. But it should do this automatically. The fact that it didn't might indicate something went wrong on install. That's why my first suggestion was just to reinstall.