https://community.dynatrace.com/t5/Troubleshooting/Troubleshooting-Application-Crashes-with-OneAgent-Without/ta-p/209246 <H1>Troubleshooting Application Crashes with OneAgent&nbsp; Without Disabling the Agent</H1> <P>When an application crashes after OneAgent installation, <STRONG>disabling the agent entirely is not necessary</STRONG> and should be avoided. Instead, use a structured, step-by-step isolation approach to identify the root cause while keeping monitoring in place.</P> <HR /> <H2>Before You Begin</H2> <P><STRONG>1. Verify technology support and agent version</STRONG></P> <P>Ensure the technology stack in use is supported by Dynatrace and that you are running the latest version of OneAgent. An outdated agent is a common source of instability.</P> <UL> <LI><A href="https://www.dynatrace.com/support/help/technology-support" target="_blank" rel="noopener">Dynatrace Technology Support</A></LI> <LI><A href="https://www.dynatrace.com/support/help/whats-new/release-notes" target="_blank" rel="noopener">Dynatrace Release Notes</A></LI> </UL> <HR /> <H2>Step 1&nbsp; Disable RUM (Real User Monitoring) First</H2> <P>Start your investigation at the RUM layer. RUM instrumentation involves JavaScript injection and HTTP response modification, which can occasionally conflict with certain application or HTTP client behaviours. Isolating RUM is the quickest and least invasive first step.</P> <P><STRONG>How to disable RUM at the Process Group level:</STRONG></P> <OL> <LI>Navigate to the affected <STRONG>Process Group</STRONG> in the Dynatrace UI.</LI> <LI>Go to <STRONG>Settings → Real User Monitoring</STRONG>.</LI> <LI>Disable <STRONG>Enable Real User Monitoring</STRONG>.</LI> <LI><STRONG>Restart OneAgent</STRONG> after making the change.</LI> </OL> <BLOCKQUOTE> <P><span class="lia-unicode-emoji" title=":light_bulb:">💡</span> <STRONG>Note:</STRONG> Disabling RUM at the Process Group level is preferred over using the OneAgent feature flag, as it also reduces configuration size by removing unnecessary application detection rules&nbsp; making it a cleaner and more efficient change.</P> </BLOCKQUOTE> <UL> <LI><A href="https://www.dynatrace.com/support/help/shortlink/rum-for-process-groups#disable-rum-for-a-process-gr..." target="_blank" rel="noopener">Detailed steps: Disable RUM for a Process Group</A></LI> </UL> <P><STRONG>If disabling RUM resolves the crash</STRONG> → Contact Dynatrace Support to investigate the specific RUM/injection conflict further.</P> <P><STRONG>If the crash persists</STRONG> → Continue to Step 2.</P> <HR /> <H2>Step 2&nbsp; Identify the Technology Stack</H2> <P>Navigate to the affected <STRONG>Process</STRONG> in the Dynatrace UI and expand the <STRONG>Properties and Tags</STRONG> section. This will list all technologies detected within that process.</P> <BLOCKQUOTE> <P><span class="lia-unicode-emoji" title=":pushpin:">📌</span> <STRONG>Example:</STRONG> A .NET-based process might show technologies such as IBM MQ, ADO.NET, and WCF. A Java-based process might show JDBC, JMS, or servlet frameworks. <STRONG>The steps that follow apply to all technologies the specific sensors you will see depend on what is detected in your process.</STRONG></P> </BLOCKQUOTE> <P>Make a note of every technology listed each one has a corresponding OneAgent sensor that can be individually disabled for testing.</P> <P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="Screenshot 2026-08-18 at 15.20.59.png"><img src="https://community.dynatrace.com/t5/image/serverpage/image-id/34026i839741C415BBE661/image-size/large?v=v2&amp;px=999" alt="Screenshot 2026-08-18 at 15.20.59.png" title="Screenshot 2026-08-18 at 15.20.59.png" /></span></P> <HR /> <H2>Step 3&nbsp; Isolate by Disabling OneAgent Sensors One at a Time</H2> <P>Navigate to <STRONG>Settings → Preferences → OneAgent Features</STRONG> and search for the sensors corresponding to the technologies identified in Step 2.</P> <P>Disable them <STRONG>one at a time</STRONG>, following this procedure for each:</P> <OL> <LI>Disable one sensor.</LI> <LI><STRONG>Restart OneAgent.</STRONG></LI> <LI>Observe whether the crash is resolved.</LI> <LI>If not, re-enable that sensor and move to the next one.</LI> </OL> <BLOCKQUOTE> <P><span class="lia-unicode-emoji" title=":warning:">⚠️</span> Only disable one sensor per test cycle and always restart OneAgent between changes. This ensures you can accurately attribute the fix to a specific sensor.</P> </BLOCKQUOTE> <BLOCKQUOTE> <P><span class="lia-unicode-emoji" title=":pushpin:">📌</span> <STRONG>Example (.NET process):</STRONG> You might test sensors such as IBM MQ, ADO.NET, and WCF individually. This is illustrative&nbsp;&nbsp;<STRONG>the sensors available to you will reflect the technologies detected in your specific process</STRONG>, regardless of the technology stack in us</P> </BLOCKQUOTE> <P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="Screenshot 2026-08-18 at 15.21.37.png"><img src="https://community.dynatrace.com/t5/image/serverpage/image-id/34027i41D1FCF2DB403818/image-size/large?v=v2&amp;px=999" alt="Screenshot 2026-08-18 at 15.21.37.png" title="Screenshot 2026-08-18 at 15.21.37.png" /></span></P> <HR /> <H2>Step 4&nbsp; Use the RUM Health Check for Additional Diagnostics (Optional)</H2> <P>If the issue appears related to RUM injection specifically, the <STRONG>RUM Health Check</STRONG> can provide rapid diagnostic insight without requiring log analysis. Issue a request to the application with the header <CODE>User-Agent: dtHealthCheck</CODE> (using cURL or Postman). The response headers will indicate the RUM sensor state and help pinpoint the layer at which the issue occurs.</P> <HR /> <H2>Step 5&nbsp; Collect Data and Raise a Support Ticket</H2> <P>Once you have identified (or narrowed down) the offending sensor, open a Dynatrace Support ticket with the following information.</P> <BLOCKQUOTE> <P><span class="lia-unicode-emoji" title=":pushpin:">📌</span> <STRONG>Note:</STRONG> The example below uses a .NET application as reference. <STRONG>The artifacts required will vary depending on your technology stack.</STRONG> Work with Dynatrace Support to confirm exactly what is needed for your environment.</P> </BLOCKQUOTE> <TABLE> <THEAD> <TR> <TH class="lia-align-center"><FONT size="3">Artifact</FONT></TH> <TH class="lia-align-center"><FONT size="3">Applies To</FONT></TH> <TH class="lia-align-center"><FONT size="3">Notes</FONT></TH> </TR> </THEAD> <TBODY> <TR> <TD><STRONG>Link to the Process</STRONG></TD> <TD>All technologies</TD> <TD>Direct URL from the Dynatrace UI</TD> </TR> <TR> <TD><STRONG>OneAgent logs</STRONG></TD> <TD>All technologies</TD> <TD>Collected from the affected host</TD> </TR> <TR> <TD><STRONG>Name of the offending sensor</STRONG></TD> <TD>All technologies</TD> <TD>Which sensor was disabled when the crash stopped</TD> </TR> <TR> <TD><STRONG>Windows Event Logs</STRONG></TD> <TD>Windows-based hosts</TD> <TD>From the time window of the crash</TD> </TR> <TR> <TD><STRONG>Class dumps</STRONG></TD> <TD>.NET applications</TD> <TD>Collected at time of crash</TD> </TR> <TR> <TD><STRONG>Memory dumps</STRONG></TD> <TD>.NET applications</TD> <TD>Recommended tool:<SPAN>&nbsp;</SPAN><A href="https://www.microsoft.com/en-us/download/details.aspx?id=58210" target="_blank" rel="noopener">Debug Diagnostic Tool</A></TD> </TR> <TR> <TD><STRONG>Heap dumps / thread dumps</STRONG></TD> <TD>Java applications</TD> <TD>Collected at time of crash</TD> </TR> <TR> <TD><STRONG>Application-specific logs</STRONG></TD> <TD>All technologies</TD> <TD>E.g., IIS logs, Node.js logs, JVM logs&nbsp; depending on stack</TD> </TR> </TBODY> </TABLE> Tue, 25 Aug 2026 13:35:35 GMT noel_david 2026-08-25T13:35:35Z https://community.dynatrace.com/t5/Troubleshooting/Troubleshooting-Application-Crashes-with-OneAgent-Without/ta-p/209246 <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> <H2>Summary</H2> <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> <H2>Problem</H2> <P><EM>*This is a mandatory section.</EM></P> <P><EM>Provide a precise description of the problem/ task to be described. Use anonymized screenshots, and include text for&nbsp;important messages, errors, or information that will help the customer find this article when searching.</EM></P> <P>&nbsp;</P> <H2>Troubleshooting steps</H2> <P><EM>*This section can be omitted as necessary.</EM></P> <P><EM>Explain what troubleshooting steps should be taken to ensure the problem matches this article.</EM></P> <P>&nbsp;</P> <H2>Resolution</H2> <P><EM>*This section can be omitted for articles that guide customers on ticket creation.</EM></P> <P><EM>Explain the solution or all possible solutions resulting from the troubleshooting steps.<BR /><BR /></EM></P> <H2>What's next</H2> <P><EM>*This is a mandatory section. Customers need a way to respond or follow up if they have questions.&nbsp;</EM></P> <P><EM>Explain what to do if the article did not help.&nbsp;</EM><EM>Note that there are multiple options available, including:</EM></P> <OL> <LI><EM><STRONG>Opening a support ticket</STRONG> - be as specific as possible about the information the customer should include in the ticket.&nbsp;</EM> If this article did not help, please open a support ticket, mention that this article was used and provide the following in the ticket: <UL> <LI>link to XYZ</LI> <LI>screenshot of XYZ</LI> <LI>information about XYZ</LI> </UL> </LI> <LI><EM><STRONG>Suggesting Product Idea</STRONG> - encourage the customer to suggest/ vote for a Product Idea explaining their business use case.</EM></LI> <LI><EM><STRONG>Explain this will change in the future</STRONG> - explain that this behaviour will change in a future release. (No product idea / support ticket needed)</EM></LI> <LI><EM><STRONG>Alternatives -</STRONG>&nbsp;any other actions or links to other articles that could move the customer forward.</EM></LI> </OL> <P>&nbsp;</P> <P><EM>*If it exists, link this article to the relevant troubleshooting map using the following guideline</EM></P> <H3>More articles can be found on the <A href="https://community.dynatrace.com/t5/Troubleshooting/" target="_self">XXX Troubleshooting Map</A></H3> </DIV> Tue, 25 Aug 2026 13:35:35 GMT https://community.dynatrace.com/t5/Troubleshooting/Troubleshooting-Application-Crashes-with-OneAgent-Without/ta-p/209246 noel_david 2026-08-25T13:35:35Z https://community.dynatrace.com/t5/Troubleshooting/Troubleshooting-Application-Crashes-with-OneAgent-Without/tac-p/212106#M195 <P>Disabling the Dynatrace Oneagent should always be the very last option. Without it you risk insight into the true issue.&nbsp;<a href="https://community.dynatrace.com/t5/user/viewprofilepage/user-id/17456">@noel_david</a>&nbsp;Thanks for sharing this!&nbsp;</P> Fri, 12 May 2023 19:08:37 GMT https://community.dynatrace.com/t5/Troubleshooting/Troubleshooting-Application-Crashes-with-OneAgent-Without/tac-p/212106#M195 ChadTurner 2023-05-12T19:08:37Z