@Rhino_Bulgaria It looks like that button is using the old bad trick (! _Reflect _Pause _RemoveExistingSymmetry) instead of the correct command which is ! _RemoveSymmetry. I don’t know when it was set to that or why it is not updated with a new installation.
You can change the definition of that button to use ! _RemoveSymmetry instead, or run the ToolbarReset command in a recent version to reset all you buttons to the current defaults.