User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Safari/537.36 Edg/92.0.902.67

Steps to reproduce:

Selected a folder within my RSS feeds.

Actual results:

The message view contains message - but all details are blank.

an error is visible in the debug log window;

Uncaught
Exception { name: "", message: "Component returned failure code: 0x80550005 [nsIMsgFolder.updateFolder]", result: 2153054213, filename: "resource:///modules/DBViewWrapper.jsm", lineNumber: 88, columnNumber: 0, data: null, stack: "updateFolderAndNotifyOnLoad@resource:///modules/DBViewWrapper.jsm:88:15\nopen@resource:///modules/DBViewWrapper.jsm:810:32\nshow@chrome://messenger/content/folderDisplay.js:849:19\nFolderPaneSelectionChange@chrome://messenger/content/commandglue.js:363:18\nonselect@chrome://messenger/content/messenger.xhtml:1:1\nMozTreeChildren/<@chrome://global/content/elements/tree.js:69:28\n", location: XPCWrappedNative_NoHelper }
DBViewWrapper.jsm:88

Expected results:

All messages should be displayed.

Just for a certain folder?
WFM.

just one folder is affected; all of the other folders work fine.

Probably the message summary for that folder is currupt. Tried Repair Folder from the folder properties?

Repair Folder fixed it up. I didn't think to look in the properties for this because I wouldn't normally expect to find actions on the properties; but that's just my opinion.

Maybe move repair folder out of the properties onto the main popup menu, (i.e. consistent with Compact Folder)

Thanks for guiding me to a solution -

Glad it worked out for you. Closing this as there's not much we could do here.