Ok so essentially your error is (for the purposes of search on the forum picking it up) -
A route named 'HomePage' is already in the route collection. Route names must be unique.
Parameter name: name
The original error pasted and some by others are generic errors. They may be completely unrelated. You would need to turn on detailed errors to see what the application is really complaining about.
I did search for this error and there is a lot of people across different applications that have had this error. If it returns, I'll contact nopcommerce in hopes of getting more insight into the issue.
Here is my response to the ticket as a resolution to other people who may be having this issue. I would be very shocked if this was a hosting environment issue so chances are others are experiencing this at other hosts as well. Since this is a 2012 server with the latest everything, it might not be an apparent bug since most people are most likely not running in this environment -
Hello,
I did quite a some research on this. It does appear to be related to either -
1) App pool recycles and reloads the dlls but the old dll information stays in the memory for whatever reason and it has redundant directives
2) The dll files inside your bin folder were not the default nopcommerce dll files
what I did:
I shut down the site. Renamed your bin folder to bin.bak and restored the bin folder from the vanilla nopcommerce 2.8 you had in your web space. I'll monitor your site and this ticket to see when and (hopefully) why it fails if it fails again.