Replacing each instance of a string literal with a constant

I looked and could only find one very old post about this and the answer is no longer valid.   I'd like to replace ALL instances of a particular string literal in a file.  Sonar finds one, I replace it and then have to do a "replace all" to catch the other ones.  I swear this has worked before but just on occasion.   Not saying there's a bug, just don't know what I did to make it work.  Just using ctrl-alt-C to do this.