Cloud agents crash -

[Robin_Weston]

Where does the bug appear (feature/product)?

Background Agent (GitHub, Slack, Web, Linear)

Describe the Bug

Unable to view a cloud agent web page, seeing a generic “Something went wrong” page. In the dev tools console, I see lots of the following errors:

My problem URL is https://cursor.com/agents/bc-03555606-c478-5a13-8a90-1b2e09cca077

98690-3a791d0eb92baf…K3mDyBoy6AqRdPmFt:1 Error: cannot encode field aiserver.v1.ConversationMessage.ToolResult.result to JSON: E(…).toJson is not a function
at Object.writeMessage (77120-739a1eea1a691e…oy6AqRdPmFt:1:26407)
at ConversationMessage_ToolResult.toJson (77120-739a1eea1a691e…Boy6AqRdPmFt:1:4306)
at ConversationMessage_ToolResult.toJSON (77120-739a1eea1a691e…Boy6AqRdPmFt:1:4457)
at JSON.stringify ()
at k (85773-5d3a32009eb335…oy6AqRdPmFt:1:74866)
at F (85773-5d3a32009eb335…oy6AqRdPmFt:1:78334)
at d (66446-9f76fac5a6d933…y6AqRdPmFt:1:118732)
at 66446-9f76fac5a6d933…oy6AqRdPmFt:1:43018
at o1 (24795f5d-69def8a2104…oy6AqRdPmFt:1:88958)
at uE (24795f5d-69def8a2104…y6AqRdPmFt:1:104850)

error-41ea2ca22c793b…K3mDyBoy6AqRdPmFt:1 [AgentsError] Error: cannot encode field aiserver.v1.ConversationMessage.ToolResult.result to JSON: E(…).toJson is not a function
at Object.writeMessage (77120-739a1eea1a691e…oy6AqRdPmFt:1:26407)
at ConversationMessage_ToolResult.toJson (77120-739a1eea1a691e…Boy6AqRdPmFt:1:4306)
at ConversationMessage_ToolResult.toJSON (77120-739a1eea1a691e…Boy6AqRdPmFt:1:4457)
at JSON.stringify ()
at k (85773-5d3a32009eb335…oy6AqRdPmFt:1:74866)
at F (85773-5d3a32009eb335…oy6AqRdPmFt:1:78334)
at d (66446-9f76fac5a6d933…y6AqRdPmFt:1:118732)
at 66446-9f76fac5a6d933…oy6AqRdPmFt:1:43018
at o1 (24795f5d-69def8a2104…oy6AqRdPmFt:1:88958)
at uE (24795f5d-69def8a2104…y6AqRdPmFt:1:104850)

Steps to Reproduce

Run any cloud agent. It’s happened on multiple agents for me and I can’t see any consistent theme

Expected Behavior

Cloud agent to run normally and I can see its progress

Screenshots / Screen Recordings

Operating System

MacOS

Version Information

Cloud Agents

For AI issues: add Request ID with privacy disabled

https://cursor.com/agents/bc-03555606-c478-5a13-8a90-1b2e09cca077

Does this stop you from using Cursor

Yes - Cursor is unusable

[deanrie]

Hey, this is a known bug. The same ToolResult.toJson error is affecting several users right now. The team is aware.

While we’re waiting on a fix, here are a couple things that might help:

• Try a different model. Based on reports in this thread, 5.3 Codex doesn’t trigger this error. Which model were you using?
• As a workaround, Safari handles this error differently and might work.

Let me know if switching models helps.