Strange Errors in c# Windows Forms Project Involving a .csx file that doesn't even exist

Question

I have a Windows Forms app I've been developing and all of a sudden two errors show up in my Errors List tab that are strange.

First, they don't prevent my app from compiling and running.

Next, they both reference a project (Submission#0) that doesn't exist in my solution and a file that exists nowhere on my system (Submission1.csx).

Aside from that they are unspectacular; one says that a ComboBox doesn't exist in the current context and the other says the type or namespace "Point" could not be found.

I've looked in the solution file; no reference to a Submission#0 project or anything unexpected. And like I said, there is no file ANYWHERE on my system that is named Submission1.csx.

I'm stumped. Any thoughts would be much appreciated.

Immaterialism

Been playing with View > Other Windows > C# Interactive? Maybe deleting the suo file will help. – Weyermann

Wow @HansPassant! I don't recall ever playing with C# Interactive, but removing the suo file cleared things up. Thanks!! – Immaterialism

The warning I got pointed to file "c:\program files\microsoft visual studio\2022\community\common7\ide\commonextensions\microsoft\vbcsharp\languageservices\InteractiveHost\Core\Submission3.csx" although I did not find it... – Grave

This mentions deleting bin/obj/.vs folder – Guyette