optimizer

[Moon1964]

every time I try to use this feature it comes up with " oops something went wrong try again or use the help button"

[nukecad]

Could you give some more deatils please?

What Windows version are you using?
If not Windows Defeder then what AV are you using (and the version number).

Are you using CCleaner Pro or CCleaner Free? (or possibly CCleaner Portable).

What app/which apps are you attempting to put to sleep?

Is there any more to that error message, or it that all it says?

A screenshot of the apps Performance Optimiser has found might help, something like this:
.

[Moon1964]

using win 10

haven't got that far to put anything to sleep 

windows defender v1  

using cccleaner pro   thats all the error said was "oops something went wrong try again "

[nukecad]

Don't you love those helpful error messages that give no clue what the problem might be, just "Something"?

The only thing I know of that won't even open Performance Optimizer to do a scan is the Portable CCleaner, even CCleaner Free can scan but it can't put apps to sleep.
Portable can't do it because PO need files to be installed.

I'd try reinstalling CCleaner, just in case the last install/update was faulty.

1. Download the 'Slim' installer (3rd one down) from here: https://www.ccleaner.com/ccleaner/builds
2. Double click the downloaded 'ccsetup613_slim.exe' to reinstall CCleaner.
   (Don't uninstall the old one first, if you do that then you will need to enter your key again in the new install - so make a note of it).
3. See if the Performance Optimiser works as it should with the fresh install.