My Screen Saver is awry & need help I have an iMac 21.5" 2.5 GHz Intel Core i5 Macintosh HD - Yosemite. My Screen Saver comes up with foreign words and gobbledygook that I don't understand.  Went into  Finder/library/Screen Savers (this is what is in my Applications) to see what I could do but there is nothing in this folder.  This looks bogus to me. Do you agree and what should I do?
Screensavers were developed do deal with issues that affected CRT displays. As nobody makes them anymore, and LCD displays don't have the same issues, we no longer need screensavers. A screensaver running on a flat screen monitor just looks pretty - there is no difference to the operation.

Open System Preferences.

Go to Desktop -> Screen Saver and set the "Start after:" value to Never.

Go to Energy Saver and set "Turn display off..." to whatever value you want.

This actually powers down the screen illumination and most of the GPU.