Trouble loading UMIK-1 Calibration file

Hi! I bought the UMIK-1 and downloaded REW, and also downloaded the calibration file for my microphone. I started REW and it asked for my calibration file, which I entered. A big red "X" appeared which, I assume, meant it didn't like something about that file. Later, when I closed then re-opened REW, it didn't ask for my calibration file, which I took to be a good thing. And the dB meter seems to be working, and the levels look reasonable. But when I go to Preferences > Cal files, there's still a big red "X" next to the calibration file. So I don't know if REW has accepted and is using the calibration file or not. How do I know? How do I get rid of that red "X"? I'm attaching a screenshot. Thanks! I'm attaching a screenshot. Thanks!

That's a button used to delete the entry if you want to remove it.

Thank you. Stupid Grok insisted the red "X" meant there's a problem!!

Perhaps the icon is a little ambiguous, especially to an AI with their love of green ticks and red crosses

I could change it:

I actually think the X is more clear than the new one. So please don't change it on my account - it seems like I'm the only one who had a problem with it and if you change it, it would probably just confuse people who are used to the way it is. I think the thing that threw me is that there was no message saying "Calibration file accepted" or something like that. If you added some positive indication that the calibration file has been accepted and is being used, that would certainly remove any ambiguity. Thank you for being so responsive!!!