Where does the bug appear (feature/product)? Cursor IDE Describe the Bug After auto-update from 3.9.16 → 3.10.20, MCP Apps no longer render — the tool result shows only text, no iframe. Same servers rendered correctly in 3.9.16. Reproduces across local stdio and remote HTTP servers, and with both t…

Hey, thanks for the report. Yeah, in 3.9.16 the widgets were rendering, and that actually explains it. If it worked back then, MCP Apps rendering must’ve been enabled for your account, and after updating to 3.10.20 that enablement got dropped. This isn’t a broken pipeline or a server-specific issue…

Following up after digging into this further - it’s a known issue on our side, and it’s the same one we’re now tracking internally. The interactive MCP App widgets aren’t mounting for setups like yours right now: the tool itself still runs (that’s why you get the text result), but the inline widget …

[image] Mohit: Does the widget fail on every tool call, or does it occasionally render? Does a window reload (Cmd+Shift+P → “Developer: Reload Window”), or toggling the MCP server off and back on in Settings, ever make it appear? If it does, that’s also a temporary workaround. I was redirect…

Thanks, this confirms it. “Fails on every call” and “reload doesn’t help” line up exactly with the known issue we’re already tracking on our side, so it’s not your servers or config, and there’s nothing to toggle or work around right now. We’ve reproduced it internally, and I’ll update this thread o…

Where does the bug appear (feature/product)? Cursor IDE Describe the Bug In Cursor 3.11.19, MCP Apps interactive UI views are not displayed when calling tools that declare a UI resource. The MCP tool executes successfully and the agent returns a text response, but the embedded interactive GUI (ifra…

It’s possible that this may have been fixed sooner than this version but I am seeing MCP apps appearing again after upgrading to Cursor 3.12.17 on MacOS.

In version 3.12.29 tool with MCP app is being called but iframe is only visible after I expand all the reasoning steps. [image]

@Cameron_Yick - yep, that’s correct. The original bug where widgets didn’t render inline at all was fixed in 3.12. Thanks for confirming. @Maxim_Soloviev - what you’re describing is a different symptom. The widget does render, but it ends up inside a collapsed group of reasoning steps (“Worked for …

Hi team, Please enable MCP Apps widget rendering for my account. Cursor login email: sicexpn@gmail.com Cursor IDE: 3.16.17 (macOS, stable) Surface: local Agent chat (New Agent), not Cloud Agent / Chat mode MCP server: globally registered in ~/.cursor/mcp.json as repo-launcher (user-repo-launcher) …

MCP Apps stopped rendering in 3.10.20 (worked in 3.9.16)

Support Bug Reports

Maxim_Soloviev (Maxim Soloviev) July 22, 2026, 7:24pm 20

@deanrie Done: MCP app is hidden by default

Topic		Replies	Views
MCP Apps: client stopped issuing resources/read; ui:// widgets don't mount (regression in 3.9.16) Bug Reports mcp	9	195	August 20, 2026
BUG: new UI prevents Cursor from authenticating with all MCP servers Bug Reports mcp	9	178	September 2, 2026
New Customize area broken for workspace-level MCPs Bug Reports mcp	12	284	August 26, 2026
Cursor doesnt see workspace/project-level defined MCP servers Bug Reports mcp	9	269	August 26, 2026
Cursor-backend-control is declared but not registered at runtime Bug Reports mcp , automations	6	124	July 28, 2026

MCP Apps stopped rendering in 3.10.20 (worked in 3.9.16)

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