Have just done a clean install of FONV, and want to use FOMM to look after installing my mods and load order issues, however I am having real trouble getting it working. After looking into it I notice it hasn't been updated for about 3 months and there doesn't appear to me much in the way of communication from FOMM's current caretakers/developers.

Game is installed and runs fine.
NVSE is installed and runs fine.

Whenever FOMM is added, the game will not load. The launcher appears, and then crashes with an error message from windows: Launcher has stopped working and needs to close.
Whenever FOMM is removed, game runs fine again.

Whats more, its not just through FOMM that the launcher crashes, while the game is installed, FONV can't be launched from the launcher.exe, through desktop shortcuts or from Steam. Every time, the same thing, the launcher crashes.

Running:
Win 7

FONV: Steam version.

Has anyone seen this before or know how to fix this? Its bugging me as I know how much effort FOMM will save me otherwise in terms of installing and running mods later.

Did you install the game to its default directory or did you install it to a custom one?

Try this.....

Download FNVedit extract it to your data folder so you have FNVedit.exe and some huge long named file with a DAT extension in the folder.

Make two more copies of the FNVedit.exe, rename one copy to FNVMasterRestore.exe and the other to FNVMasterUpdate.exe

Now you should have

FNVEdit.exe
FNVMasterRestore.exe
FNVMasterUpdate.exe

Now, run FNVMasterUpdate, this will add an ESM flag to all of your ESP files, and it will also sort your load order to something better.

Now start FOMM, click on Start NVSE and see if the game starts.

Also, look at this thread
http://www.gamesas.com/index.php?/topic/1166249-bug-game-crashes-at-the-first-loading-screen/

Thank you, I don't know why that worked but it did.

You have made the rest of my weekend significantly more enjoyable. If you would care to shed a little light on the issue I would appreciate it, however this fixed it.

Thanks again.

Most likely you installed something wrong. a Crash on start sounds like a missing master to me.

It was something strange but not an incorrectly installed mod, game was working when FOMM wasn't installed, with mods working fine.

Either way, FNVedit fixed it.

You're welcome!
As far as shedding light on to why FNVMasterUdpate worked for you and me, I claim "Magic", because I have no other clue as to why it does what it does.