Most error patterns in Claude Desktop have known causes. Before I touch the configuration, I take three diagnostic steps \u2013 that saves considerable time in practice.<\/p>\n\n\n\n
Open the log file.<\/strong> On macOS under Check the Anthropic status.<\/strong> A glance at status.anthropic.com rules out that the error lies outside your own setup. That tends to save hours of misdirected searching.<\/p>\n\n\n\n Isolate the network path.<\/strong> Tethering via your phone quickly shows whether VPN, proxy, or Zscaler is responsible. If the app works on the hotspot, you know where to look.<\/p>\n\n\n\n Black or blank screen on start.<\/strong> Cause: GPU conflict or corrupted cache. Delete the cache directory, disable hardware acceleration, restart.<\/p>\n\n\n\n App loads endlessly, spinner turns.<\/strong> Cause: network blockade by VPN, proxy, or Zscaler. Allow api.anthropic.com, test briefly without VPN.<\/p>\n\n\n\n 403 Forbidden or “invalid authorization”.<\/strong> Cause: token expired or region header altered. Create a new token, check plan status, examine the proxy for header manipulation.<\/p>\n\n\n\n 500 Internal Server Error.<\/strong> Cause: a server problem on Anthropic’s side. Check status.anthropic.com, retry after five minutes.<\/p>\n\n\n\n Hammer icon missing, no MCP servers visible.<\/strong> Cause: syntax error in claude_desktop_config.json or wrong command path. Run a JSON lint, set paths absolute, restart the app completely.<\/p>\n\n\n\n App starts, closes immediately on Linux.<\/strong> Cause: missing system libraries. Start the app from the terminal, read the error message, install the missing packages.<\/p>\n\n\n\n Zscaler.<\/strong> When Zscaler re-signs the traffic, Claude Desktop rejects the certificate. Solution: exclude api.anthropic.com from TLS inspection or place the Zscaler root certificate in the system trust store.<\/p>\n\n\n\n Intune.<\/strong> App packages for Intune need the right detection path. Skip it, and you only see the app on devices after manual intervention.<\/p>\n\n\n\n Authenticated proxy.<\/strong> Set HTTPS_PROXY and HTTP_PROXY in the system context, not only in the user shell. Otherwise the app does not use the proxy and runs into timeouts.<\/p>\n","protected":false},"excerpt":{"rendered":" Black screen, spinning loader, missing hammer icon: most Claude Desktop errors have known causes. I show how I narrow them down systematically.<\/p>\n","protected":false},"author":1,"featured_media":1465,"comment_status":"","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[],"class_list":["post-1416","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-automatisierung"],"_links":{"self":[{"href":"https:\/\/pletzenauer.com\/en\/wp-json\/wp\/v2\/posts\/1416","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pletzenauer.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pletzenauer.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pletzenauer.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pletzenauer.com\/en\/wp-json\/wp\/v2\/comments?post=1416"}],"version-history":[{"count":0,"href":"https:\/\/pletzenauer.com\/en\/wp-json\/wp\/v2\/posts\/1416\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pletzenauer.com\/en\/wp-json\/wp\/v2\/media\/1465"}],"wp:attachment":[{"href":"https:\/\/pletzenauer.com\/en\/wp-json\/wp\/v2\/media?parent=1416"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pletzenauer.com\/en\/wp-json\/wp\/v2\/categories?post=1416"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pletzenauer.com\/en\/wp-json\/wp\/v2\/tags?post=1416"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}~\/Library\/Logs\/Claude<\/code>, on Windows in %APPDATA%Claudelogs<\/code>, on Linux under ~\/.config\/Claude\/logs<\/code>. The last 50 lines reveal the problem in most cases.<\/p>\n\n\n\nSymptom index: the most common error patterns<\/h2>\n\n\n\n
What often goes wrong on a corporate network<\/h2>\n\n\n\n