I’ve re-installed several times. The result is always the same.
The Editor.log file contains the following :
@doublemax That did it! Thanks for your help.
I had the same problem for two days after the update to unity5.4.2F1 I tried everything including this site, nothing works, so I went to unity icon on my desktop and right click and search for compatiblity and window said that unity is not compatible and I have window10, so I tried another way and uninstall it and install it again, but this time I choose 32 instead 64 version and it worked.
I think that is the problem by saying not compatible, so change it to 32 verion and it will work.
thank you