Suddenly receiving "Return without GoSub" error when opening default form

We have been using the Asset Tracker database template downloaded from Microsoft without issue for a few weeks. This morning we started receiving a message box displaying "Return without GoSub" when the default form opens. Clicking OK closes the message and the form opens but then displays the following:

The #Name? is a link that says either "New" or "Open" that then opens a form displaying the details of the current asset . I am not aware of any changes being made to the form or any of the code behind the form, and it worked fine yesterday. When we click the link now, we get the "Return without GoSub" message box again, and clicking OK then displays the following:

I've looked in the embedded Macro, which we have NOT modified, and cannot find "Return" anywhere. In addition, there is no "Return" in the two VBA modules that are in the database. I've done basic VBA in the past, but nothing with the new embedded macros, so I am really at a loss here as to how to fix this. Any ideas/suggestions? We were hoping to start performing a physical inventory of PCs, etc., on Monday, so of course this pops up today!