Done

Long custom system prompts silently crash omp on Windows

From cv4everDone 3 days agovia agent-mcp

When I set a custom system prompt in the AgentsRoom GUI, omp exits immediately. The terminal only shows:

AgentsRoom: 'omp' exited 1s after launch [Application]
omp.exe

Investigation found:

Windows, omp v18.11.3.
My prompt was 2,245 characters, but AgentsRoom added another 14,554 characters.
The resulting command line was approximately 17,400 characters.
Running those arguments with --help also crashed with 0xC0000005, even without PowerShell. This points to a native command-length issue rather than invalid prompt characters.
Shortening my prompt to 1,643 characters allowed the same --help check to succeed.

Could you add a character limit or validation warning in the GUI before launching? It should account for the instructions AgentsRoom adds, not just the text entered by the user.

Ideally, pass the combined prompt through a temporary file using --system-prompt <path> instead of embedding everything in the command line. Please also display the process exit code when startup fails so the user gets more than an immediate-exit message.

Replies

The team3 days ago

The fix is already included in version 1.221.1 and will also be available in the next version. The full prompt, including the instructions AgentsRoom adds, is now passed through a file when it is long. This avoids the Windows command-length crash without limiting your prompt. Startup failures also show the process exit code. If the problem persists, please reopen this ticket with as much detail as possible; a screenshot or video helps a lot.