I ran into this issue when I was creating a module based on DNN Task Manager Module Development video. I had named my modules using underscores " example_SM_Example ". Once I ran the build under release mode my entire DNN site was broken returning a "404.`15 The request filtering module is configured to deny a request where the query string is too long" error. I did NOT create any virtual directories. I tried the fixes for that error by looking for the <request> tag in the app.config and the web config but it didn't exist. Any additions to the web or app config completely tanked the site.
I finally blew the site away and started from scratch. The 2nd time, I did away with the underscores in my nomenclature and had no problems.
I finally blew the site away and started from scratch. The 2nd time, I did away with the underscores in my nomenclature and had no problems.