"Load More Posts" & "ARCHIVE" will not work on blog

Hello,

Since the upgrade the “load more posts” at the bottom of my blog will not load. It’s completely disabled, and therefore my other posts are not able to be accessed. Also, the archive button is not working. It’s taking people back to my homepage. These issues have never been a problem before. Please note that I have checked all settings and nothing has changed.

Please kindly tell me what is going on and how this can be fixed. I’m very concerned, and I need this remedied as soon as possible. Thanks!

Kindest Regards,
Erin