> For the complete documentation index, see [llms.txt](https://docs.devolutions.net/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.devolutions.net/server/knowledge-base/troubleshooting-articles/http-error-500.md). # HTTP Error 500 Covers common HTTP 500 error variants in Devolutions Server, including IIS module and ASP.NET Core startup failures, and their respective fixes. There are many different HTTP Error 500 types, each with their own solution(s). This topic contains the most commonly encountered. *** ### 500.19 - Internal Server Error When trying to load the Devolutions Server web page, the following error is displayed in the browser: *HTTP Error 500.19 - Internal Server Error* *The requested page cannot be accessed because the related configuration data for the page is invalid.* This error is due to the absence of the IIS ASP.NET Core Module (ANCM) and/or the IIS Rewrite Module, as seen in the IIS #### Solution 1. From the Devolutions Server Console, edit the instance. 2. Open the ***Support*** tab. 3. Click on the ***IIS diagnostic*** button. 4. Click on ***Install prerequisites***. {% hint style="info" %} If running the PowerShell script from the Devolutions Server Console is blocked due to restrictions on the system, the script is located in the ***Scripts*** folder of the Devolutions Server Console installation folder. {% endhint %} *** ### 500.19 - Internal Server Error (ASP.NET) The ***HTTP Error 500.19 - Internal Server Error*** is triggered by an ASP.NET issue at line 60. The solution is to edit the `` in the `web.config` file located in the Devolutions Server Console installation folder. #### Solution 1. To locate the installation folder, open Devolutions Server Console and click ***Explore***. 2. Find and open the `web.config` file. 3. Replace the `` with: ```xml ``` 3. Save the file. 4. Restart the Devolutions Server Console. *** ### 500.30 – Enable the workspace TrustServerCertificate option Most of the time, Devolutions Server returns this 500.30 error when an SQL server (Azure or local) is configured with a self-signed certificate not found in the certificate store. #### Solution In ***File*** – ***Workspaces***, choose the workspace experiencing the 500.30 error. Then go to ***Edit workspace*** – ***Advanced*** and set the ***TrustServerCertificate*** to **true**. *** ### 500.30 - ASP.NET Core app failed to start Following the upgrade process, when trying to open the Devolutions Server web page, the browser displays ***HTTP Error 500.30 - ASP.NET Core app failed to start***. #### Solution Verify that ***Enable 32-bit applications*** is set to ***False*** in the Devolutions Server application pool's ***Advanced settings*** in IIS Manager. If ***Enable 32-bit applications*** is already set to false, ensure that the service account designated as the ***Application pool identity*** in the ***Devolutions Server application pool*** has enough rights on the App\_Data subfolder in the ***Devolutions Server web application folder***. Make sure that the APS.Net Core Hosting Bundle installed on the server where Devolutions Server is hosted is the [latest version](https://dotnet.microsoft.com/en-us/download/dotnet). *** ### 500.30 - The transaction log for database '\' is full due to 'LOG\_BACKUP' This occurs when the transaction log of the Devolutions Server database has filled up because log backups have not been performed, preventing the log space from being reclaimed. **Solution** 1. Back up the transaction log to free up internal space for reuse: ```sql BACKUP LOG TO DISK = 'C:\Backups\MaBase_log.trn'; ``` To check the transaction log space usage, run: ```sql DBCC SQLPERF(LOGSPACE); ``` *** ### 500.31 - Failed to load ASP.NET Core runtime When updating Devolutions Server to the latest version, the web UI displays ***HTTP Error 500.31 - Failed to load ASP.NET Core runtime***. The reason is that the ASP.Net Core version is not updated on the server where Devolutions Server is hosted. #### Solution 1. Update the Devolutions Server Console to the latest version. 2. Download the latest [ASP.Net Core Module hosting bundle](https://dotnet.microsoft.com/en-us/download/dotnet/10.0). 3. Install it on the server where Devolutions Server is hosted. {% hint style="info" %} Contact our customer support technicians at if these solutions do not solve your problem. {% endhint %} *** ### 500.37 - ASP.NET Core app failed to start within startup time limit The Devolutions Server instance is currently unable to establish a connection with the configured Identity provider, preventing the completion of the authentication process. To resolve this issue, please review your network environment and ensure that no firewall settings, proxy rules, or other network configurations are blocking or interfering with the communication between the Devolutions Server host and the Identity provider. *** ### 503 - The service is unavailable The 503 error occurs when the web server of Devolutions Server is not reachable. This error can have many causes, it is therefore recommended to use Windows’ Event Viewer to troubleshoot the issue (under ***Windows Logs*** – ***System***). #### The request never reaches Devolutions Server If the site returns a 503 error and no matching entry appears in the IIS log, the Devolutions Server log or the Event Viewer, the request is answered by the Windows HTTP.sys driver before it reaches Devolutions Server. To investigate: 1. Check the HTTP.sys error logs in `C:\Windows\System32\LogFiles\HTTPERR`. 2. Run the following commands in an elevated command prompt to review the HTTP.sys request queues, URL reservations and SSL certificate bindings: ``` netsh http show servicestate view=requestq netsh http show urlacl netsh http show sslcert ipport=0.0.0.0:443 ``` A frequent cause is another product that reserved the port and left the reservation behind after being uninstalled. This is notably the case with **Windows Admin Center**: version 2 uses port 443 by default (version 1 used port 6516, so upgrading it, for example with `winget upgrade`, can move it to port 443), and its URL reservations remain after it is uninstalled. In this situation, Devolutions Server keeps returning a 503 error on port 443 but works on any other port. #### Solution 1. Remove the leftover reservations from an elevated command prompt (adjust the port if needed): ``` netsh http delete sslcert ipport=0.0.0.0:443 netsh http delete urlacl url=https://+:443/ netsh http delete urlacl url=http://+:80/ ``` 2. Run `iisreset`. 3. In IIS Manager, make sure the Devolutions Server **site** is started, not only its application pool. IIS stops a site that failed to bind to its port and does not restart it automatically. {% hint style="warning" %} Only delete reservations that belong to a product that is no longer installed. Removing the reservation of an active application will break that application. {% endhint %} {% hint style="info" %} Contact our customer support technicians at if these solutions do not solve your problem. {% endhint %} --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. 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