I'm in the process of setting up a new CRM (and DB) server. I've imported my solutions (only 5 - our internal one, Process JS, DyanmicsCRM2016Workflows, and Ribbon Workbench), and I can see everything just fine. I can create records, all is dandy. So in the new system I decided to try a couple of new modifications. I added a couple of fields, and all was great. Until...I tried to add a currency field to one of our custom entities. Then everything just died a horrible death. I immediately started getting 404 errors on the entire site. I restored the db from backup and tried again, to confirm - same thing. I can create other field types in that entity just fine, and I can create currency fields in other entities. Just this one particular combination sets the whole thing on fire. I tried enabling CRM and IIS trace logs, but the IIS ones still just gave me the same 404 message (which was a regular file not found, even on the server with all friendly-errors turned off), and even with logging turned on on the CRM server I get nothing in the log dir.
I'm completely stumped. Anyone have any clue as to what might be happening, or even where else I can look?