Close constantly

I have SketchUp Make 2016 64b, in Windows 8.1. I have only the plugin Kerkythea and i have 2 problems:
1- Sketchup close automatically after a few minutes, two or three.
2- I can´t remove kerkythea because i can´t find this at folder "plugin", and although i unmark it from preferences it don´t dissapears from sketchup and continue closing.

Are you sure that Kerkythea is installed to the proper file path?
The directories for the various versions of SU plugins folders are as follows - try looking in these places:

The standard SketchUp Plugins root directories are:
Windows SU8: C:\Program Files\Google\Google SketchUp 8\Plugins
Windows SU13: C:\Program Files\SketchUp\SketchUp 2013/Plugins
Windows SU14: C:\Users\<username>\AppData\Roaming\SketchUp\SketchUp 2014\SketchUp\Plugins
Windows SU15: C:\Users\<username>\AppData\Roaming\SketchUp\SketchUp 2015\SketchUp\Plugins
Windows SU216: There are 2: C:\ProgramData\SketchUp\SketchUp 2016\SketchUp\Plugins and C:\Users\your user name\AppData\Roaming\SketchUp\SketchUp 2016\SketchUp\Plugins (Twilight Render uses the first one which installs for everyone who uses the computer. The second installs only for the current user.)

Mac SU8: Macintosh HD/Library/Application Support/Google SketchUp 8/SketchUp/Plugins
Mac SU13: ~/Library/Application Support/SketchUp 2013/SketchUp/Plugins
Mac SU14: ~/Library/Application Support/SketchUp 2014/SketchUp/Plugins
Mac SU15: ~/Library/Application Support/SketchUp 2015/SketchUp/Plugins
Mac SU16: ~/Library/Application Support/SketchUp 2016/SketchUp/Plugins

where '~/Library/..." is the same as "/Users/<your_mac_user_name>/Library/..."
Also, OSX has a habit of hiding the ~/Library folder (to protect mac users from themselves, apparently).