Blender disappeared after upgrading my Ubuntu 15.04 to 15.10 - unmet dependency error for installing it

Question

Here is the screen-shot of the error.

Answer 1

Check the file /etc/apt/sources.list which probably contains the reference to the ppa repository of blender. The third argument in the line has to be vivid for version 15.04 and wily for version 15.10. Probably, you are mixing software and libraries from both versions.