article Browser monitors: 401 failures on challenge-response pages in Troubleshooting https://community.dynatrace.com/t5/Troubleshooting/Browser-monitors-401-failures-on-challenge-response-pages/ta-p/233029 <DIV> <H2><STRONG>Summary</STRONG></H2> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">This article explains why Dynatrace Browser monitors may fail with <STRONG>401 Unauthorized errors</STRONG> on challenge‑response pages and how to resolve or work around the issue.</DIV> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">These failures typically occur when applications use dynamic authentication or bot‑protection mechanisms that are incompatible with Synthetic browser execution.</DIV> </DIV> <P>&nbsp;</P> <P><LI-TOC indent="15" liststyle="disc" maxheadinglevel="3"></LI-TOC></P> <P>&nbsp;</P> <DIV> <H2><STRONG>Problem</STRONG></H2> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">When executing a Dynatrace Browser monitor:</DIV> <UL> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">The monitor fails with a <STRONG>401 Unauthorized error</STRONG></LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Execution does not progress past initial request</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Authentication or security challenge blocks the test</LI> </UL> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">This often occurs on:</DIV> <UL> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Login pages</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Applications with bot protection</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Systems using challenge‑response authentication</LI> </UL> <HR /> <H2><STRONG>Error Behavior</STRONG></H2> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">Common symptoms include:</DIV> <UL> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">HTTP <STRONG>401 Unauthorized</STRONG> responses</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Unexpected redirects or failed navigation</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Monitor unable to load the target page</LI> </UL> <HR /> <H2><STRONG>Cause</STRONG></H2> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">This issue occurs because <STRONG>challenge‑response authentication flows</STRONG>:</DIV> <UL> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Require <STRONG>dynamic interaction</STRONG> (tokens, cookies, JavaScript execution)</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Detect and block automated browsers</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Depend on <STRONG>runtime-generated values</STRONG> that cannot be reused</LI> </UL> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">Dynatrace Synthetic Browser monitors:</DIV> <UL> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Run with a <STRONG>clean browser session each time</STRONG></LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Cannot persist or replay dynamic authentication tokens</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">May be identified as automated traffic</LI> </UL> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">As a result: → Authentication fails, leading to <STRONG>401 responses</STRONG></DIV> <HR /> <H2><STRONG>Resolution</STRONG></H2> <H3><span class="lia-unicode-emoji" title=":white_heavy_check_mark:">✅</span> <STRONG>Option 1 – Use supported authentication methods</STRONG></H3> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol"> <OL start="1"> <LI> <P>Use HTTP authentication in the browser monitor settings.</P> <UL> <LI>In browser clickpaths, <STRONG>Enable HTTP authentication</STRONG> and provide credentials in the <A title="Learn about the event types created when recording a browser clickpath." href="https://docs.dynatrace.com/docs/shortlink/id-brower-clickpath-events#navigate" rel="noopener" target="_blank">Navigate event</A>.</LI> <LI>In single-URL browser monitors, select <STRONG>Advanced setup</STRONG> in edit mode and <STRONG>Enable global login authentication</STRONG>. Then select <STRONG>HTTP authentication</STRONG> and provide credentials.</LI> </UL> <P>Read more in <A title="Learn how to configure authentication methods for monitoring web applications and API endpoints in Synthetic Monitoring." href="https://docs.dynatrace.com/docs/shortlink/synthetic-authentication" rel="noopener" target="_blank">Supported authentication methods in Synthetic Monitoring</A> and <A title="Learn about configuring browser monitors and clickpaths." href="https://docs.dynatrace.com/docs/shortlink/browser-monitors-config" rel="noopener" target="_blank">Configure browser monitors</A>.</P> </LI> <LI> <P>Additionally, you might need to ignore the 401 status code in browser monitor settings in edit mode. Select <STRONG>Advanced setup</STRONG> and turn on <STRONG><A title="Learn about configuring browser monitors and clickpaths." href="https://docs.dynatrace.com/docs/shortlink/browser-monitors-config#ignore-status-codes" rel="noopener" target="_blank">Ignore specific status codes</A></STRONG>.</P> </LI> </OL> </DIV> <HR /> <H3><span class="lia-unicode-emoji" title=":white_heavy_check_mark:">✅</span>&nbsp;<STRONG>Option 2 – Work with application/security teams</STRONG></H3> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">If the application uses:</DIV> <UL> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">CAPTCHA</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Bot detection</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Token-based challenges</LI> </UL> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">Consider:</DIV> <UL> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Whitelisting Synthetic traffic</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Allowing known test endpoints</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Providing alternative authentication paths</LI> </UL> <HR /> <H3><span class="lia-unicode-emoji" title=":white_heavy_check_mark:">✅</span> <STRONG>Option 3 – Validate behavior outside Dynatrace</STRONG></H3> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">Before troubleshooting further:</DIV> <UL> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Confirm requests succeed in a standard browser</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Identify where the authentication flow breaks</LI> </UL> <HR /> <H2><STRONG>Important Notes</STRONG></H2> <UL> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">This is a <STRONG>limitation of challenge‑response mechanisms</STRONG>, not a Dynatrace defect</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Synthetic monitors cannot always replicate: <UL> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Anti-bot protections</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Advanced authentication workflows</LI> </UL> </LI> </UL> <HR /> <H2><STRONG>When to Use This Guide</STRONG></H2> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">Use this article when:</DIV> <UL> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Browser monitors return <STRONG>401 Unauthorized</STRONG></LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Pages include advanced authentication or bot protection</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Recording works, but execution fails</LI> </UL> <HR /> <H2><STRONG>Best Practices</STRONG></H2> <UL> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf"><span class="lia-unicode-emoji" title=":white_heavy_check_mark:">✅</span> Test simple, stable endpoints for Synthetic monitoring</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf"><span class="lia-unicode-emoji" title=":white_heavy_check_mark:">✅</span> Avoid CAPTCHA and bot-protected flows</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf"><span class="lia-unicode-emoji" title=":white_heavy_check_mark:">✅</span> Use synthetic-friendly authentication mechanisms</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf"><span class="lia-unicode-emoji" title=":white_heavy_check_mark:">✅</span> Validate clickpaths carefully during recording</LI> </UL> <HR /> <H2><STRONG>What’s Next</STRONG></H2> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">If the issue persists:</DIV> <DIV class="paragraph-in-scc-markdown-text ___1ngh792 ftgm304 f1iaxwol">Provide Dynatrace Support with:</DIV> <UL> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Monitor URL and configuration</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Execution results and screenshots</LI> <LI class="___ccc16d0 fje8fi8 f1ng9h0j f1bwykku f18jd3zf">Description of authentication flow</LI> </UL> </DIV> <P>&nbsp;</P> <H3>Related reading</H3> <P><span class="lia-unicode-emoji" title=":open_book:">📖</span>&nbsp;&nbsp;<A class="" href="https://community.dynatrace.com/t5/Troubleshooting/Synthetic-Troubleshooting-Map/ta-p/250426" target="_blank" rel="noopener">Synthetic Troubleshooting Map</A></P> <P><span class="lia-unicode-emoji" title=":open_book:">📖</span>&nbsp;&nbsp;<A style="background-color: #ffffff;" title="Learn about the event types created when recording a browser clickpath." href="https://docs.dynatrace.com/docs/shortlink/id-brower-clickpath-events#navigate" rel="noopener" target="_blank">Navigate event</A></P> <P><span class="lia-unicode-emoji" title=":open_book:">📖</span>&nbsp; <A title="Learn how to configure authentication methods for monitoring web applications and API endpoints in Synthetic Monitoring." href="https://docs.dynatrace.com/docs/shortlink/synthetic-authentication" rel="noopener" target="_blank">Supported authentication methods in Synthetic Monitoring</A>&nbsp;</P> <P><span class="lia-unicode-emoji" title=":open_book:">📖</span>&nbsp;&nbsp;<A title="Learn about configuring browser monitors and clickpaths." href="https://docs.dynatrace.com/docs/shortlink/browser-monitors-config" rel="noopener" target="_blank">Configure browser monitors</A></P> <P><span class="lia-unicode-emoji" title=":open_book:">📖</span>&nbsp; <A title="Learn about configuring browser monitors and clickpaths." href="https://docs.dynatrace.com/docs/shortlink/browser-monitors-config#ignore-status-codes" rel="noopener" target="_blank">Ignore specific status codes</A></P> Fri, 12 Jun 2026 08:53:50 GMT nandini_balakri 2026-06-12T08:53:50Z Browser monitors: 401 failures on challenge-response pages https://community.dynatrace.com/t5/Troubleshooting/Browser-monitors-401-failures-on-challenge-response-pages/ta-p/233029 <P><LI-TOC indent="15" liststyle="disc" maxheadinglevel="2"></LI-TOC></P> <DIV class="lia-message-template-content-zone"> <P>*<EM>Use a table of contents for longer articles.&nbsp;</EM></P> <H1>Summary</H1> <P><EM>*This is a mandatory section.</EM></P> <P><EM>Short description of which part of the Dynatrace platform the article refers to and what kind of problem it will help resolve / task it will describe.</EM></P> <P>&nbsp;</P> <H1>Problem</H1> <P><EM>*This is a mandatory section.</EM></P> <P><EM>Provide a precise description of the problem / task to be described.</EM></P> <P>&nbsp;</P> <H1>Troubleshooting steps</H1> <P><EM>*This section can be omitted.</EM></P> <P>&nbsp;</P> <H1>Resolution</H1> <P><EM>*This section can be omitted for ticket‑creation articles.</EM></P> <H1>What's next</H1> <P><EM>*This is a mandatory section.</EM></P> </DIV> Fri, 12 Jun 2026 08:53:50 GMT https://community.dynatrace.com/t5/Troubleshooting/Browser-monitors-401-failures-on-challenge-response-pages/ta-p/233029 nandini_balakri 2026-06-12T08:53:50Z Re: Browser monitors: 401 failures on challenge-response pages https://community.dynatrace.com/t5/Troubleshooting/Browser-monitors-401-failures-on-challenge-response-pages/tac-p/233725#M522 <P>Great guide:) Thank you&nbsp;<a href="https://community.dynatrace.com/t5/user/viewprofilepage/user-id/19886">@nandini_balakri</a>&nbsp;</P> Tue, 09 Jan 2024 10:14:25 GMT https://community.dynatrace.com/t5/Troubleshooting/Browser-monitors-401-failures-on-challenge-response-pages/tac-p/233725#M522 radek_jasinski 2024-01-09T10:14:25Z