What prevents you from opening Read messages?

I haven't the foggiest. I click on read messages and nothing happens. A glitch in Thunderbird? Who knows

I click on read messages

Please be more specific about what you're doing. Is 'read messages' a folder? Or one message which you were able to open before (hence 'read'), and cannot open anymore now? Multiple messages?

In case it helps illustrating the problem, please post a screenshot. https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem

When I open the Thunderbird application I am presented with a list of options one of which is READ MESSAGES. When I click on this option, NOTHING HAPPENS. I cannot see any of my messages, not a list, nothing. Its as if the link doesn't exist. I am however able to compose a new message. This is less than helpful as I am trying to get some pictures downloaded from a message that I was told that was sent to me but I have not been able to access any messages, new or old. The Inbox does not appear as a tab as it did previously so I have to assume that the list of options presented are folders...............

Please post a screenshot.