MS-Access error messages

After a compile, I get error messages (Network connection failed) and it seems that all stop, back, forward, new, find functions are gone. Even the link from the switchboard are not functioning anymore. I get the debugger every time I click on a button, but there everything seems to be ok.

Now, when i click on the relationship button, access closes down. I am unable to check my relationship.

Any idea why this behaviour?