Epic Games Launcher stuck on Resume after UE 5.8.2 update – manifest commit never completes

General Issues and Bug Reporting (Unreal Engine)
1

Summary

Epic Games Launcher gets stuck in a Resume loop after updating Unreal Engine 5.8.1 to 5.8.2.

The engine files are successfully updated to UE 5.8.2 / CL 56702186, and BuildPatch reports ProcessSuccess=TRUE / ErrorCode=OK. However, the Launcher fails to commit the final installed manifest and returns to Resume without downloading anything.

The Launcher log shows:
IncompleteInstall=1 AutoResume=1
followed by:
completed, waiting for manifest commit before starting next download

There is also a suspicious MainGameAppId mismatch where the valid on-disk AppId is reconciled against catalog=(null):(null):(null).

What Type of Bug are you experiencing?

Other

Steps to Reproduce

  1. Have Unreal Engine 5.8.1 installed through Epic Games Launcher.
  2. Start the update to Unreal Engine 5.8.2.
  3. Allow the update to finish.
  4. Observe that Epic Games Launcher changes the engine state to “Resume”.
  5. Click Resume/Update again.
  6. The operation runs for only a few seconds, downloads no additional engine data, and returns to “Resume”.
  7. Check UnrealEditor.exe properties or Engine/Build/Build.version:
    • File version: 5.8.2.0
    • Product version: ++UE5+Release-5.8-CL-56702186
  8. Check the Launcher log. BuildPatch reports success, but the installation remains marked as incomplete and waits for a manifest commit.

Expected Result

After BuildPatch successfully completes the UE 5.8.2 update, Epic Games Launcher should commit the new installed manifest, clear the incomplete-install state, and display Unreal Engine 5.8.2 with the Launch button.

Observed Result

The Unreal Engine files are already UE 5.8.2 / CL 56702186, but Epic Games Launcher continues to report the previous 5.8.1 installation state and shows Resume.

Repeated Resume/Update attempts do not download additional data.

The log reports a successful BuildPatch operation, followed by:

IncompleteInstall=1 AutoResume=1

and:

completed, waiting for manifest commit before starting next download

The manifest commit does not complete.

A related warning appears immediately before this:

MainGameAppId mismatch detected for app UE_5.8
on-disk=ue:18b3b415bc434c5b974f50488360ca31:UE_5.8
catalog=(null):(null):(null)
Correcting to catalog value.

Affects Versions

5.8

Platform(s)

Windows

Upload an image

UnrealEditor_Details.png
UnrealEditor_Details.png607×864 19.2 KB
Launcher_UE582.png
Launcher_UE582.png1920×2160 440 KB
UE581_Update.png
UE581_Update.png418×274 56.6 KB
UE581_Resume.png
UE581_Resume.png389×238 28.1 KB

Additional Notes

Additional diagnostics:

The physical Unreal Engine installation was already fully updated to UE 5.8.2 / CL 56702186 before the Launcher UI was fixed.

The main UE 5.8 manifest matched the 5.8.2 build, and BuildPatch completed with:
ProcessSuccess: TRUE
ErrorCode: OK
FailureReasonText: The operation was successful.

The issue was isolated to the Launcher metadata/final manifest commit stage.

For diagnostic purposes, after backing up the original metadata and with Epic Games Launcher completely closed, I manually reconciled the installed UE_5.8 metadata to the already-installed 5.8.2 manifest and removed only the stale UE 5.8 pending transaction files.

After restarting Epic Games Launcher, it immediately displayed:
Unreal Engine 5.8.2
Launch

No additional Engine files had to be downloaded.

I have preserved the original installed .item, pending .item, manifests and Launcher logs if Epic needs them for investigation.

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