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After trying to add an MCP server and figuring out why “no tools found” keeps happening I made a change to the build\index.js script to try if that would resolve the issue and this change caused cursor to become totally unusable. I suspect that when the added script causes EverythingProvider to crash, it makes cursor completely unusable. I can’t close the window, open files and the only way to stop cursor is by killing the process, which shows it’s using 14% cpu and seems to be stuck on some stuck subprocess (I presume EverythingProvider). Killing the process throws this error:
Unfortunately cursor immediately restores the last project and automatically executes the MCP server commands again after a restart, so you end up in a loop.
The only way I managed to get out of this loop was by renaming the MCP server’s index.js file it tried to run on start to prevent the crash and delete the server.
Additionally, I find the MCP server management to be incomplete overall. It requires a lot of digging to figure out why not tools can be found. There is too little information to debug the issue and figure out A: if the server starts correctly or B: what stdio commands are exchanged between the server and the client. At the bare minimum there should be a MCP server log available where the user is able to see what’s happening, which requests are made to the server and which responses are received by the client with a trace if they fail.