I've seen that this problem has been reported several times going as far back as 2013. Subsequent versions of MC haven't fully addressed it, so I thought it would be helpful to anyone experiencing this issue to know the appropriate solution for Windows PCs. (This may also work on Mac, if Mac has an equivalent setting).
The problem is in Windows' own internal DPI scaling. In my case, I have 3 monitors. Monitor 1 and 2 (primary and secondary) are set to 125% scale at 4k. Monitor 3 is set to 100% at 1080p. I run MC on Monitor 3.
It seems MC is ignoring the 100% dpi setting on Monitor 3, and instead scaling based on Windows' 125% setting for the others.
Good news - this effect can be disabled.
Right-Click your MC shortcut and choose "properties"
Click the "compatibility" tab
Click "change high dpi settings" (a new dialog will open)
Put a checkmark in the bottom checkbox in the "high dpi scaling override" section.
Click the pulldown just below it, and choose "application"
Click OK to close the pop up dialog, then "apply" to close the original.
Finally if MC is running, close it
Now run MC.
When it opens, no more blurry text. Your fonts will be shown slightly larger than normal (scaling up to the setting for the primary monitor), but this can easily corrected by reducing their size in MC's fonts setting. Mine were originally set to Calibri 11, and scaled down nicely to Calibri 9.
Hope this helps someone!
Best,
Marc
