[BUG] If MCP is not setup the "Robot advice" is not disabled and crashes application

[joshdbe]

Component

Desktop App (Windows)

Performance Studio Version

1.19.1

Operating System

Windows 11

Describe the Bug

If MCP is not setup the "Robot advice" is not disabled and crashes application

Steps to Reproduce

If MCP is not setup the "Robot advice" is not disabled and crashes application

Expected Behavior

If MCP is not setup the "Robot advice" is disabled

Actual Behavior

If MCP is not setup the "Robot advice" is not disabled and crashes application

Plan File

No response

Screenshots

No response

[erikdarlingdata]

Thanks for the report. I checked the premise against the source before anything else, and it changes the shape of this one:

Robot Advice doesn't use MCP — in your version or any version. It serializes the current plan's analysis to JSON and shows it in a window, so you can paste it into whatever AI or tooling you like. The MCP server is a separate, optional feature (Tools → MCP), and Robot Advice is supposed to work with MCP unconfigured — so "disabled when MCP isn't set up" wouldn't be the right behavior even in a perfect world. The two being unrelated in code means MCP setup won't change what you're seeing.

The crash is real, though, and I think I know which one it is. In 1.19.1 that button serializes the analysis with no guard, and a plan that's deep enough throws mid-serialize — Avalonia doesn't guard click handlers, so the exception takes the whole app down with no dialog. That's issue #430, and it's already fixed: the payload now has a depth ceiling and the button reports a failure in the status bar instead of dying. The fix is in the nightly build (since 2026-08-16) and will be in the next stable release.

One thing would confirm it (or catch it being something else): 1.19.1 writes a stack trace to

%LocalAppData%\PerformanceStudio\crash.log

when it dies like this. If the newest entry there mentions JsonException or a serializer depth error, this is #430 and the next release has you covered. If it says anything else, paste it here — that would be a different bug and I want it. Either way, if you're able to try the nightly with the same plan, that's the fastest proof.

Leaving this open until one of those confirms it.

[joshdbe]

Yes, looks like it is depth error. crash.log

[erikdarlingdata]

Thanks for grabbing the log — that settles it. Both entries in there are the same crash, and it's exactly #430: JsonException with the depth-64 message, a path thirty Children deep, thrown from the serialize call at QuerySessionControl.Advice.cs line 52. I checked the frames against the 1.19.1 source and they line up — that line serializes the analysis with no guard around it, and since Avalonia doesn't guard click handlers, the exception takes the whole process down. Your plan is roughly thirty operators deep, and each operator costs two JSON levels, which blows through System.Text.Json's default depth ceiling of 64. That's on the app, not on your plan — a plan being deep should never be fatal.

The fix is already merged to dev in f6f53c7 (PR #431): every serializer that writes an analysis now runs with a 1024 depth ceiling, and the Robot Advice handler catches serialization failures and reports them in the status bar instead of dying. It will be in the next stable release; it's been in the nightly since 2026-08-16 if the crash is getting in your way before then.

Sorry it bit you twice in one day. Leaving this open alongside #430 and closing both when the release ships.

[joshdbe]

I got this in PerformanceStudio-win-x64-1.19.1-pr426-entra-test that you gave me

[erikdarlingdata]

That explains it — PerformanceStudio-win-x64-1.19.1-pr426-entra-test was built from the Entra MFA branch, whose tip is 2026-08-11. The Robot Advice fix landed on dev on 2026-08-16, five days later, so that build predates it. Nothing is wrong with your test; that binary simply doesn't contain the fix. The PR426 build was only ever meant to test the Entra sign-in path.

For the crash, the nightly is the one to grab, or the next stable release.

While confirming this I went back through #430's fix and found it was one file short of complete, so thank you for making me look twice. The depth ceiling got applied to Robot Advice, the MCP tools, and analyze, but querystore builds its own serializer options and never got it — so planview querystore has still been failing on deep plans, quietly, one ERROR row in summary.txt per plan instead of a crash. That's fixed in #438, with a test that walks every command's options instead of trusting me to remember them all next time.

Doesn't affect what you hit, which was the desktop app and is genuinely fixed. Still leaving this and #430 open until the release ships.

[erikdarlingdata]

Shipped in v1.20.0. Grab that instead of the pr426 test build and Robot Advice will behave.

Thanks for grabbing the crash log — that is what turned this from "probably #430" into certainty, and chasing it down is what surfaced the missed querystore call site as well.