Moved to the Bridge forum.
Mini Bridge always requires Bridge to be active for showing the content of the Bridge files. If you start mini bridge in PS without having Bridge itself zctive a message should appear that you have to launch Bridge and also a launch button to do the task for you.
In Bridge first select the file that appears corrupted in MB and with right mouse click menu choose 'purge cache for selection'. If this is not working first try a reset of the preferences for Photoshop ( on a Mac this is restart PS with holding down shift, option and command key, should be something similar in Windows)
This might work for MB but also resets the other PS prefs to factory default so you have to set your custom wishes again. Not a big deal but you have to be aware of this :-)
Same can be done for Bridge itself with restart Bridge and holding down control key and choose reset preferences. But if your first attempt with purge cache for selection works you can choose the menu tools in Bridge and while having the folder content of the problem files in the content panel choose cache/ purge cache for folder and let it rebuild.