I have just installed mono and mono develop. I followed the instructions on the mono website and added and then updated the mono repositories before installing using zypper through terminal.
However when I try to open mono develop it says that an unhandled exception has occurred and I can proceed any further or even close the program without using xkill.
The error says,
System.NullReferenceException: Object reference not set to an instance of an object
at GLib.Object.NotifyCallback (IntPtr handle, IntPtr pspec, IntPtr gch) [0x00000] in <filename unknown>:0
Is a bug.
I found others have already reported the bug in bugzilla, I added some additional log info.
Despite the errors, I’ve found that you can click on all those error dialog boxes and eventually you’ll get a working app. I’ve just recently decided to take another look at it (I was extremely disappointed a couple years ago), have found many issues addressed… Although remains to be seen how well it works, I’m happy to finally see an integrated debugger. I’ve comiled and run a test app in the debugger, added tools to the toolbox and verified that app history works.
So, at least in my early investigation the errors you’re seeing are “only” irritating annoyances, when you finally get to the app it looks like it’s working.