That looks like it could be the php version. If your host has recently changed the php version they give you, ask them how to swap it back again.

Another possibility is the default settings for warnings on your host. Again, ask them if they have changed it and how to set it back again.

Machighways response to me was: "for the issue that you're having, we would not be able to revert to an earlier version of PHP, nor specify for your account to use an earlier version as it is now a security risk, and outdated.
You will need to upgrade Concrete5 manually or correct the Strict Standard errors that the site is displaying."

They offered no further help or instruction. I am not a developer nor web savvy enough to delve into the cPanel, hence my original post.

Thanks for your response, I have received several offers to help.

For a quick fix, try typing 'Debug' into the Intelligent Search box at the right of your toolbar and choose 'Debug Settings'. Set this to 'Don't show errors'. It might work. Worth a shot.

Another option might be to use a local, standalone php server, like wamp or mmamp, with the older version of php that you need. Update locally, now you don't need the older version anymore, push to the live site and you're all good.