I’ve built a small application. Just something I threw together with a
friend during a hack-session at the client. (It’s a dot
voting application and
you can try it here, if it’s up :))
As we wanted something out there fast we built it with
NancyFx and
MongoDB (a first for me) and we host it on
AppHarbor with continuous delivery via
GitHub.
Since all of these (saved Mongo) has served me well in the past I was
very surprised when we ran into problem.
When a commit is pushed to AppHarbor the application is compiled and the
test (if any) are run. That worked fine for us but then a stage is run
that’s called “Site precompilation”.

That failed with the following error:
> ```
> error ASPCONFIG: Could not load file or assembly 'Nancy.ViewEngines.Razor.BuildProviders' or one of its dependencies. The system cannot find the file specified.
> ```
This had me for quite awhile when I got a tip on "disabling
precompilation". In fact, the log tells me so also, at the very
bottom:
> ```
> Website precompilation failed with exit code 1. Precompilation can optionally be disabled in application settings
> ```
The only thing was that I didn't understand the log. Hmmm ... haven't I
been here before?

OK, cutting to the chase
here. The last part of the log comes
from [AppHarbor](https://appharbor.com/) In fact the precompilation is
a [AppHarbor](https://appharbor.com/) thing that can be turned off.
Go to \[your application\]-\>Settings-\>Build and click the "Disable
precompilation"-button. It's enabled by default.
That made my application compile and being deployed. Where back on the
[SuperDuperHappyPath](http://elegantcode.com/2011/11/23/a-year-of-the-super-duper-happy-path/).
That problem cost us a lot of trial and error... and frustration. But
now you don't have to experience the same thing.