Hi all. Have been struggling to get Agent to run with Sonnet 3.5 for past 3 days. Every time I try I get “Unable to reach Anthropic”. However, it works on Normal.
Running on Pro plan + usage based for any overages. Have tried restarting Cursor, opening a fresh Composer, but neither worked.
Whats weird is that when I used Cursor on a different laptop, it worked… Any advice?
Hey, have you tried this in a new Composer session? Also, could you share a screenshot of the error?
having the same problem. Restarting cursor, changing network or opening new composer session still fails
request ID (example) 637763ca-5e07-46c9-8827-ece239e32f0f
i had this yesterday in the evening for 1 hour yea
Had the same issue those last days (kinda weird as it wasn’t consistent) and figured that removing some of the MCP servers I had fixed the issue (really not ideal though)
the same here, downgrade cursor to 0.44 via “GitHub - oslook/cursor-ai-downloads: all cursor ai version download links, and some older versions offer a better user experience” could work temporarily, yet fall to fail finally 
be forced to use chat rather than composer until the Cursor team solve it ASAP
in addition, I found that the failed conversations were also included in Pro Usage Events and consumed the requests of premium models, which increased from 310 to 320
at the same time, even with the system proxy on, I tried to configure my own OpenAI api and it failed to verify.
I still reckon the problem is with the Cursor proxy or network tunnel.
wish the Cursor Team could fix it ASAP.
another solution: uninstall and reinstall Cursor, yet the chat history shall be lost
yeah mcp seems to be the cause for me, really weird…
Fixed by simply disabling MCP servers. Thank you all.
