Fix Intune Error 0x87D00324: The installer exited 0, but the detection rule evaluated false after it ran, so the app is reported as failed.

Root causes

• The rule checks the wrong registry view. A 32-bit installer, or a 32-bit install command, writes under WOW6432Node while the rule reads the 64-bit hive.
• A version rule uses "equals" but the installer writes a different string (1.4 versus 1.4.0.0) or a build number that changes on every release.
• An MSI product code detection rule was copied from the previous version; most vendors issue a new product code for each release.
• The installer is a bootstrapper that returns 0 while a child process is still copying files, so detection runs too early.
• A per-user installer ran as SYSTEM and wrote to the SYSTEM profile or HKCU, which a machine-wide rule never sees.
• A custom detection script writes to STDERR, returns nothing on STDOUT, or exits non-zero even when the app is present.

Step-by-step remediation

1. 1In AppEnforce.log find the exit code line and the detection state that follows it. Exit code 0 followed by NotDiscovered confirms the rule, not the installer, is failing.
2. 2On a device where the app installed correctly, check the real install location, registry key and version in the 64-bit and 32-bit views.
3. 3Rebuild the rule from those observed values. Prefer "greater than or equal" for versions, and a file or registry rule over a product code for apps that update themselves.
4. 4Run the detection script as SYSTEM (psexec -s -i powershell.exe). It must write to STDOUT and exit 0 only when the app is present.
5. 5Re-deploy to a pilot device and check three states: not detected before install, detected after install, not detected after uninstall.