Sudden Failed Request - Invalid Verb During Visual Studio Debugging

Question

During development, I unexpectedly started getting the following error message

Bad Request - Invalid Verb

HTTP Error 400. The request verb is invalid.

The developed website was launched on ISSExpress through Visual Studio. It stopped working in blue without any configuration changes.

I use: ASP MVC, C #

What could be the reason?

Answer 1

It turned out that the problem was caused by ... invalid cookie.

The solution was to delete all cookies.

(I accidentally checked the page in another browser and worked there.)