Built in Monodevelop won't open on lion

I’ve just installed Unity for the first time. I am trying to edit a script using Monodevelop, the built-in one. But it never opens, not even when I double click on in on finder. No error messages nothing.

I am using Unity 3.4.1 on MacOS Lion on a Macbook Pro 15"

I had the same problem, and while the answer for mine was pretty specific to me, how I tracked it down might help you: Open the Console app, and take a look at the MonoDevelop logs. Mine (should be the same for you) were under the FILES section on the left, under ~/Library/Logs/MonoDevelop/MonoDevelop.log. (Alternatively, you can just navigate to that directory and look at the log file directly.) That should give you some detail about what exactly the error is, so you can debug the problem.

Mine was related to a permissions error on ~/.config, for reasons which aren’t of interest here. I was getting something to the effect of “Unauthorized” or “permission denied” when MD tried to access it. I fixed the permissions, and MD opens as it should.

Good luck!

Just wanted to confirm that installing the latest(2.10.9) Mono runtime package for Mac fixed it for me.,Installing the latest(2.10.9) Mono runtime package for Mac fixed it for me.