Where does the bug appear (feature/product)?
Somewhere else…
Describe the Bug
Two MCP servers are configured in Cursor Desktop version under “Tools & MCP”. Both MCPs work with external systems:
- ERP AS/400
- Salesforce
The MCP servers are deployed on a Microsoft Azure virtual machine, are always accessible, and use streamable-http.
A system prompt describing the expected behavior and interaction between the MCPs is configured in “User Rules”.
Our internal team uses Cursor on different operating systems (Windows and macOS). We have a demo scenario where a user interacts with both systems via Cursor chat: creating data in Salesforce and updating data in AS/400 with the help of AI. Some user queries require both MCP servers to be used simultaneously.
This scenario worked correctly throughout October, November, and the beginning of December on all operating systems without any issues.
Timeline:
December 16:
We installed Cursor for a customer located in the USA (most of our team is located in Europe). The customer’s Cursor was configured identically to our internal setups.
- Both MCP servers were visible in “Tools & MCP”
- Connection icons for both MCPs were green
- Tool lists for both MCPs were visible
However, when the customer tried to run the demo scenario in chat, Cursor refused to work and returned messages such as:
“I cannot access the MCP AS/400 and MCP Salesforce.”
At the same time, everything continued to work correctly for our internal team on both Windows and macOS. We could execute any MCPs’ tool through Postman. We were also able to run the same MCP servers locally, and Cursor worked as expected.
December 17:
We configured and ran Windows virtual machine, installed Cursor, and configured it in the same way.
We observed the same issue as on the customer’s side December 16th:
- MCPs were visible in “Tools & MCP”
- Connection icons were green
- Tool lists were visible
- Despite this, MCPs were not accessible from chat
After some time, Cursor on the virtual Windows machine started working correctly again, but only in some newly opened chats. Other chats continued to show the same “MCP not accessible” messages. Throughout the day, Cursor behavior was unstable: periods of normal operation alternated with periods of failure.
In the middle of the afternoon on December 17, while testing Cursor on the virtual machine, Cursor installations on our personal Windows and macOS computers also started exhibiting the same issues.
Current status as of December 18:
- Cursor works as expected on the Azure virtual machine
- Cursor does not work on some of our personal computers
- Some colleagues who had never installed Cursor before installed it recently, and it works for them
Troubleshooting steps taken (on local computers, virtual machine, and customer side):
None of the following steps resolved the issue:
- Enabling/disabling different VPNs
- Settings → Network → Run Network Diagnostic (no issues detected)
- Settings → Network → Switching between HTTP versions (1 / 1.1 / 2)
- Checking Cursor logs (no errors found)
- Settings → Models → Leaving only one model enabled / switching between models
- Deleting the system prompt
- Running the same MCP servers locally instead of using remote MCPs
- Restarting Cursor multiple times
- Restarting computers multiple times
- Using different subscription types: Free Trial and Pro
Steps to Reproduce
- Install Cursor on a Windows or macOS machine.
- Configure two MCP servers under “Tools & MCP” using streamable-http:
- AS/400 MCP server
- Salesforce MCP server
- Verify that:
- Both MCP servers are visible in “Tools & MCP”
- Connection icons for both MCP servers are green
- Tool lists for both MCP servers are visible
- Configure a system prompt in “User Rules” that describes interaction between both MCP servers.
- Open a new chat in Cursor.
- Send a user request that requires simultaneous usage of both MCP servers
(e.g. create data in Salesforce and update related data in AS/400 in one request). - Observe Cursor chat behavior.
- (Optional but frequently reproducible) Open several new chats and repeat step 6 in each chat.
Expected Behavior
If MCP servers are visible in “Tools & MCP” with green connection status and available tools, Cursor chat should be able to access and use them consistently.
Actual behavior:
Cursor intermittently reports that MCP servers are not accessible, even though their status appears healthy in the UI. The issue affects different machines inconsistently and appears to change over time without configuration changes.
Screenshots / Screen Recordings
Operating System
Windows 10/11
MacOS
Current Cursor Version (Menu → About Cursor → Copy)
Version: 2.2.20
VSCode Version: 1.105.1
Commit: b3573281c4775bfc6bba466bf6563d3d498d1070
Date: 2025-12-12T06:29:26.017Z (6 days ago)
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Darwin arm64 24.6.0
For AI issues: which model did you use?
Composer 1, different versions of GPT 5.x
Additional Information
MCP configuration used:
{
“mcpServers”: {
“as400-mcp-server”: {
“type”: “streamable-http”,
“url”: “http://azure_address:8083/api/mcp”
},
“salesforce-mcp-server”: {
“type”: “streamable-http”,
“url”: “http://azure_address:5000/mcp”
}
}
}
Does this stop you from using Cursor
Sometimes - I can sometimes use Cursor