Three different symptoms, each with its own cause.
Nothing happens, or it closes again
Is OBS Studio, or another program built on it, running? That is the most common cause. Close it and try again — see alongside an existing OBS.
Check the rights on engineconfig. The program has to be able to write there; a machine where that folder was locked down starts and closes again.
It hangs on the loading screen
The line under the wordmark says which stage it is in:
| It says | Meaning |
|---|---|
| Starting up… | The program is loading |
| Loading modules… | The modules are starting — the usual place to hang |
| Building the interface… | The window is being assembled |
| Starting playouts… | Previews and outputs are coming up |
Stuck on modules is nearly always one of them waiting for something: a network drive that is not there, a service that does not answer, antivirus scanning the process.
After about 15 seconds the program carries on without its modules and says so; switch the suspect module off under Settings → Modules. Then find out what it was waiting for.
It starts but looks like plain OBS
Two causes:
You started the wrong thing. Start from the launcher shortcut on the desktop or in the Start menu, never the executable inside enginebin.
The installation is incomplete. If files in the program folder are missing or were renamed, you get plain OBS. Reinstall over the top — that keeps your settings.
The modules report that they cannot start
You get a window titled Modules could not start, whose message names the cause: Windows refused to start upmod-runner.exe, upmod-runner.exe is missing, upmod-runner.exe started but did not respond, upmod-runner.exe did not start in time, or The installation is incomplete.
None of these stop the program. You lose what the modules provided; the cue list, the outputs and the broadcast keep working. A missing file and an incomplete installation need a reinstall; the others are nearly always antivirus, and the message names the folder to add to its exclusions — see Settings → Modules.
When you need help with it
Send the log. It records exactly how far the start got and what it was doing — see sending logs.