Oh, Hallelujah! So, I double-checked against your picture, and everything was exactly the same...and still not working. But your comment about reinstalling the portable version made me think to open MO and hit the "instance selection dialogue" button. I selected the portable version, and loaded back in. The ONLY difference I could see was that the currently open profile and MO's style both reverted to default. All of my mods, profiles, and other settings were still there, and nothing had visibly changed in the MO base folder. But Relinker WORKED this time. So, to add to the list of stuff to try for anyone else who runs into the problem: Reselect the portable instance of MO2, even if your folders appear to be where they should be.