MonoDevelop crashes on start when last placed on 2nd monitor with MacOS 10.13 High Sierra.

It will run properly as long as it's closed while on the 1st monitor. "Displays have separate spaces" option in Mission Control settings has no effect, MonoDevelop will crash with either setting, if it's on 2nd monitor when closed.

If you run it on 1st monitor, move it 2nd monitor to work and then move back to 1st before closing it will run properly.

Steps:
1. On macOS10.13 Run MonoDevelop, by default, it should run on the 1st (main monitor)
2. While open, move it to 2nd monitor
3. Close MonoDevelop
4. Run MonoDevelop,
Result: MonoDevelop crashes

Reproduced with: 2017.3.0b3, 2017.2.0f2, 2017.1.1p3, 5.6.3p4 and all earlier versions.

Workarounds:
A) delete MonoDevelop settings folder (MonoDevelop-Unity-5.0) in Preferences.
B) have only one (main) monitor and run MonoDevelop

FIXED:
Make sure you update to the newest version of MonoDevelop using Unity Installer and set External Script Editor to MonoDevelop (built-in).