We have hit a strange issue which I cannot find any reference to while searching the web.
We have a small number of ASP.Net MVC based apps on a web server which fail after their app pools have recycled.
The default/home returns a blank page, and if you try to go to other pages you get a 404. IIS still serves static content such as css or js if you specifically go to them.
Nothing is recorded in the Win or IIS logs as errors or warnings, nothing stands out.
We can resolve the issue by either redeploying the app or deleting the sites compiled files in the Temp ASP.Net folder, forcing a recompile. But obviously once app pool recycles again it breaks.
The only thing that's changed on the box is a installing .Net Framework 4.7.2 along with a few Win Updates.
However dev versions of the same app or on another box which work fine and that's also been updated to 4.7.2 etc.
How can I solve this?