Ok, so, my visual studio is broken. I say this NOT prematurely, as it was my first response to see where I had messed up in my code. When I add controls to the page I can\'t
In my case new asp controls I added to an existing were not being detected.
What worked for me was forcing a recompile by renaming an existing control to break the build eg: changing to
When I corrected the ID and rebuilt a new designer file was generated with the corrected ID and new controls.