Well, it seems 95% of the posts i make on this site are asking for help But the community is really helpful so it is literally my go to place to find fixes because many are down to my stupidity, anyway down to business, i recently installed Mod Organizer and really don't know the ins and out, but whenever i try to install a mod that comes with a scripted installer (Fallout Character Overhaul, Mod Config Menu, Weapon Mod Menu.....etc) The window comes up saying "launching external installer, then i get a error message saying "Installation Failed"
                                                                                                  The file exists
And i have googled it and i cannot find any solutions so i hope someone here has had the same problem and knows of a fix it would be greatly Appreciated thank GUN

Screenshot:

That is quite odd. I actually have only used mod organizer, never nmm or fomm and I have never had this issue. Are you sure that the mod files aren't corrupted? Also make sure Mod organizer is up to date and it is set for Fallout new vegas and not another game. One more thing, try downloading manually and downloading with manager to see if it makes a difference.

@SwiggedySwoody Yup Downloaded newest version, tried each mod 3 times installing reinstalling, definitely set for new vegas don't have a clue whats going on.

I've never had this issue either, sounds abit strange, maybe try downloading the files manually and unpack them to see if you get any errors?

In some cases, I've found, it is necessary to do a manual install of FOMOD files because Mod Organizer isn't too great at handling them. In any case, do a manual install, check the file structure to make sure it is correct (all the files you want are pulled to their correct places in one folder, then uncheck the others, as they should be empty anyway) Data (set directory)
--->meshes, textures, sound, etc.
--> Various files

Thanks but is Mod Organizer really worth the Trouble, what can it do that FOMM and NMM can't do Except from Profiles and having it's own ini Files?

@rest_in_pepperoni I have just found that it is very easy to install and uninstall mods with it, but a large problem is that it attempts to install mods from installers that were never built for Mod Organizer, but were built for NMM or FOMM. I would try just going in the mod's folders, dragging what you want out, and then making that a .rar file and installing it. That is if you're still using it.

@rest_in_pepperoni Mod Organizer can't read FOMOD's properly, I usually just install those files with FOMM.

It still is strange though as I have been able to install all of those without error... Maybe someone can help you at the nexus on the mod page. And maybe using an older version would work for you?

Yeah, i've installed also most of them and they work just fine, but I believ he is using the FOMOD rather than the rar file itself, so that could be the problem, maybe.

I've had no trouble with installing these mods with MO, i'm using v1.2.18 though and it appears a new version was released little over a week ago (v1.3., what version are you using rest_in_pepperoni?

All solved now guys, Cleared the Temp folder in AppData and use FOMM for fomod files like mpaz suggested, thanks everyone helping

happy to hear that pepperoni.