Solving "Could not load file or assembly" problems on mono

So once again I have been tearing my hair out for hours trying to solve this problem.
Specifically in my case it was mod-mono-server2.exe that was producing this error. Now I *know* that that file exists - I checked, in fact that was the assembly I was executing.
So it must be one of the dependencies - but which one?
It turns out there IS a way to find out.
By setting 2 environment variables before attempting to run the application you can get some debugging information which tells you exactly what files mono was trying to find when it errored.

The 2 variables in question are:
MONO_LOG_LEVEL=info MONO_LOG_MASK=asm
So if you run
MONO_LOG_LEVEL=info MONO_LOG_MASK=asm mono myapp.exe
You will get a stack load of debugging info on the console, and just before the exception you should see some lines which looks something similar to this:
Mono-INFO: Assembly Loader probing location: '/usr/lib64/mono/gac/mod-mono-server2/2.10.0.0__0738eb9f132ed756/mod-mono-server2.dll'. Mono-INFO: Assembly Loader probing location: '/usr/lib64/mod-mono-server2.dll'. Mono-INFO: Assembly Loader probing location: '/usr/lib64/mono/gac/mod-mono-server2/2.10.0.0__0738eb9f132ed756/mod-mono-server2.exe'. Mono-INFO: Assembly Loader probing location: '/usr/lib64/mod-mono-server2.exe'. Handling exception type FileNotFoundException
Bingo! It's looking for an assembly called "mod-mono-server2"
But wait a minute! That's the assembly I'm running!

And no - I have no idea why it can't find it when I've actually given it the path to look in!
But since I can see where it is looking a quick symbolic link solves my issue:

ln -s "/usr/local/lib/mono/2.0/mod-mono-server2.exe" /usr/lib64/
This is probably a bad idea, there must be a good reason why it can't find it in the correct location.

Now I'm getting a different error about non-blocking sockets.

*sigh*

Installing MONO on CENTOS

I've spent literally hours tearing my hair out trying to get this sorted so I thought I would share what I have found here:

Most of the search results on google are out of date and/or contain links which no longer work.

I also tried compiling everything from source but ran into trouble here too.

Eventually after much headscratching I found a solution :)

Take a look at this page: http://fedoraproject.org/wiki/EPEL

Ignore that this is a fedora project as it works just fine on centos.

Part way down the page under the "How can I use these extra packages?" heading are a couple of links. Choose the one that is appropriate to your version of centos. e.g. I am using centos 6 so I used the "newest version of 'epel-release' for EL6" link.

Download the rpm file and install it.
You should probably verify the rpm before installing, but I couldn't work out how and I was loosing patience by this point!

rpm -i epel-release-*.noarch.rpm
Now you should be able to search for and install the mono packages (and others) using yum.

e.g.
yum install mono-core mono-data mono-devel mono-extras mono-web mono-winforms monodoc mono-web-devel
N.B. there is no monodevelop included in this lot.
And I can't find anywhere to get it either :(