I have been using microsoft and ccleaner for a long time and never had this same issue that happened to me today. I tried updating and got the error but ccleaner updated after like the fifth try without the slim installer. I will believe that it's either something within the ccleaner software or the two not playing well together before I think it's microsoft's issue alone but I will keep the slim installer idea in mind should this happen again and I can't get ccleaner to update since it worked for Banballow.
You literally reposted what you posted above which is unnecessary and redundant. You may "suspect" all you like but I didn't need to download the slim version because it updated as per usual, updating within the ccleaner (as people should if they do not have auto update on) you may be incorrect, but then you may be right. No need to reply.