Messenger not loading on a iPad 5

There are many reports of issues with Messenger. Many users also report that deleting both the FaceBook and Messenger Apps from the iPad, prior to restarting and reinstalling the Apps, will resolve the problem. Perhaps this will also work for you:

Delete apps on your iPhone, iPad, and iPod touch - Apple Support

Force restart iPad - Apple Support

After restarting the iPad, install and launch Messenger App first - and then reinstall the FaceBook App:

• Messenger

https://apps.apple.com/gb/app/messenger/id454638411

• FaceBook

https://apps.apple.com/gb/app/facebook/id284882215

You are very welcome.