Update to 5.50.6911 not working

Tried to update to version 5.50.6911 and get the error message "Error opening file for writing: C:\program Files\CCleaner\CCleaner64.exe. Can abort, Retry or Ignore, Ignore results in the same error message bit for the ....\branding.dll file. Needless to say skipping both fails to install the update. Have toggled off Malaware Bytes Real time protection but get same result. Any idea how to fix?

See if this helps

https://forum.piriform.com/topic/53053-cant-update-550-pro/