BlogTroubleshootingPosts tagged Troubleshooting.1 postsSearch postsSearchAllNotesChecklistGuideMCPMigrationRankingRegistryRemote serversSecurityServer developmentSmitheryStatisticsSyncTool descriptionsTransportsTroubleshootingNov 1, 2026NotesMCP server not showing up or failing to start? Causes and fixesThe error you see, usually "Connection closed", is a symptom. This guide goes through the nine causes behind most failed MCP servers, with real error text we reproduced and the fix for each, on Claude Desktop, Claude Code, Cursor and VS Code.13 min readRead post