Steam can't update Common Reddist, won't let me launch games unless it's updated and is now stuck in an update loop.
I try to launch a game, Steam wants to update Common Reddist. It tries, it uses 100% of the Ethernet but 0% of the disk, it dies at 13% and says "Corrupt Download". It has already downloaded the files into the Downloading folder tho. I try again, it fails again. It wont let me launch the game unless Common Reddist is done updating, which it cant. I try it all, I get a clean copy of the files with Depot Downloader, put them where Steam wants them, then update the appmanifest file so that StateFlags is set to 4, BytesToDownload and BytesDownloaded set to 0, StagedDepots all clear, TargetBuildID matching the current BuildID and LastUpdated set to today. It worked once, I got the game running, then next Steam restart and it starts trying to update Common Reddist all over again, repeating the miserable cycle. I can't think of anything else to try. And no, clearing download cache only worked once and setting the appmanifest file to read only makes Steam spit out a "Disk Write Error" while still trying to update Common Reddist and still wont allow the game to launch