We have a Kenwood KDW8ST2A

Question

We have a Kenwood KDW8ST2A Dishwasher which is about a month old. The other day we had to pull it out from under the worktop because something rolled under it. When we put it back and went to use it later that day, we got an E1 error code appear and it's been like that since. We pulled it back out to make sure that we hadn't accidently pulled or loosened any of the pipes. We have the manual which does tell us what the error means but it doesn't tell us how to fix it. I'm sure it must be something we did when pulling it out. Can anyone help.