Windows Smart App Control blocks Prowlarr.Host.dll

I attest that there is not an existing issue for this?

• I have searched the existing open and closed issues

I attest this is not related to a Cardigann YML Indexer.

• I confirm this is not related to a Cardigann YML Indexer

Current Behavior

Prowlarr 2.5.2.5491 intermittently fails to start as a native Windows service while Smart App Control is enabled and enforcing the VerifiedAndReputableDesktop policy.

During a cold boot, the automatic service start and subsequent retry attempts terminated while loading Prowlarr.Host.dll:

System.IO.FileLoadException: Could not load file or assembly 'C:\ProgramData\Prowlarr\bin\Prowlarr.Host.dll'. An Application Control policy has blocked this file. (0x800711C7)

Service Control Manager then reported a 30-second startup timeout. Code Integrity events 3033 and 3077 identify policy ID 0283ac0f-fff1-49ae-ada1-8a933130cad6. The DLL is unsigned and has no Zone.Identifier alternate stream.

Sometimes when I restart it manually it fixed the problem.

Sonarr, Bazarr, Seerr does not have this problem only Radarr and Prowlarr reproduce this problem every time I restart my PC.

I tried to reinstall to fix the problem, it did not work.

Expected Behavior

The official Windows release should start normally with Smart App Control enabled.

Please consider Authenticode-signing the shipped Windows binaries, including the application DLLs, with a trusted certificate.

Steps To Reproduce

1. Install Prowlarr 2.5.2.5491 as a native Windows service.
2. Enable Windows Smart App Control enforcement.
3. Restart Windows.
4. Wait for the delayed Prowlarr service to start.
5. Prowlarr exits while loading Prowlarr.Host.dll.
6. Check the Application and .NET Runtime event logs for error 0x800711C7 and Code Integrity events 3033/3077.

Environment

OS: Windows 11 Pro N 25H2, build 26200.8894
Prowlarr: 2.5.2.5491
Branch: master
Install: Native Windows service
Docker Install: No
Using Reverse Proxy: No
Service Account: NT AUTHORITY\LocalService
.NET: 8.0.27 / CoreCLR 8.0.2726.22922
Smart App Control: On, enforcement mode

What branch are you running?

Master

Trace Logs?

Attached:

• prowlarr-trace.txt - genuine Trace-level controlled startup capture
• windows-code-integrity.txt - exact Code Integrity and .NET Runtime failures
• environment.txt

The blocked process terminates during .NET assembly loading, before a new Prowlarr process initializes its application logger. Consequently, the 0x800711C7 exception cannot appear inside the Prowlarr trace file itself; it is captured by the attached Windows event evidence. The trace file shows the controlled startup immediately preceding the blocked restart.

environment.txt prowlarr-trace.txt windows-code-integrity.txt

I attest that Trace Logs have been provided as applicable. Reports will be closed if the required logs are not provided.

• I attest that I have read and followed the steps in the wiki link above and provided the required trace logs - the logs contain trace - that are relevant and show this issue.