Upcoming Disruption of Service Impacting Unreal Engine Users on GitHub

We are actively working to resolve a disruption of service that impacts Unreal Engine users on GitHub.

Anyone downloading fresh copies of Unreal Engine code from GitHub will experience a disruption of service when running the Setup script that fetches dependencies, indicated by a “Failed to download” error message. Those with existing copies may receive an error when data is unable to refresh.

We are prioritizing access to Unreal Engine 5.2 and UE5-Main and aim to have them available today, May 5th. From there we will prioritize restoring additional versions, starting with the most recent and working backward in this order: 5.1.1, 5.0.3, 4.27.2, 4.26.2, and 4.25.4. Please be aware that sub-versions and other versions not listed may not be restored.

We apologize for any disruption to your workflows and will provide updates as versions are restored.

Thank you for your understanding.


For Unreal Engine 4.25 and later, you should be able to successfully pull from the official release branch or you may optionally replace the XML file, as described below. Any release older than that, you must replace the XML file to successfully download the data required to build and run the engine.

To remedy the error in the builds, a new Commit.gitdeps.xml file has been attached to each release version as an asset. Please replace the existing Engine/Build/Commit.gitdeps.xml file with the new asset.

The complete list of releases with new XML files: 4.11.0-5.1.1

If you’re seeing this issue for UE5-Main, please do a fresh pull/fetch to this commit or later.


The branches for UE5-Main, 5.2, 5.1, and 4.27Plus have been updated to address the error.

We are continuing work on additional versions.

1 Like

This could warrant being a red banner on your Github page imho


The following versions have also been updated:

  • 4.25
  • 4.26-chaos
  • 4.27
  • 4.27-chaos
  • 5.0

Is this related to the Epic Launcher marking most binary engine versions as “Update Available”? Or is that a separate issue?


Thank you. Let me try again

Sorry, the 5.11 version still looks like this

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5.2 also has error this error


Thank you Amanda.

Please, could you updaload the 4.27 Launcher version with the 4.27-plus one, instead? That would be great!

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I still get a 403 Forbidden on branch 5.0

$ ./Setup.bat
Checking dependencies...
Updating dependencies:   0% (0/88498)...
Failed to download 'http://cdn.unrealengine.com/dependencies/UnrealEngine-17461838/010dd3c65d5732a23e4ba678d73c9306ee039ef3': The remote server returned an error: (403) Forbidden. (WebException)
Press any key to continue . . .

Do we have an ETA on a fix for 5.1.1?

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It is getting a little ridiculous, this is slowing down a lot of my progress right now.

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I agree, this has completely killed my workflow, as I am unable to build the engine whatsoever :confused:

Issue has NOT been fixed for version 5.1.1 This is getting to be very frustrating and there is no need for this sort of disruption.

  Checking dependencies...
  Updating dependencies:   0% (0/97340)...
  Failed to download 'http://cdn.unrealengine.com/dependencies/UnrealEngine-18966385/00b99f0240e4a4e89f9cb877cc7b7ff64e496f52': InvalidDataException: The archive entry was compressed using an unsupported compression method.
     at System.IO.Compression.Inflater.Inflate(FlushCode flushCode)
     at System.IO.Compression.Inflater.ReadInflateOutput(Byte* bufPtr, Int32 length, FlushCode flushCode, Int32& bytesRead)
     at System.IO.Compression.Inflater.ReadOutput(Byte* bufPtr, Int32 length, Int32& bytesRead)
     at System.IO.Compression.Inflater.InflateVerified(Byte* bufPtr, Int32 length)
     at System.IO.Compression.DeflateStream.ReadCore(Span`1 buffer)
     at System.IO.Compression.DeflateStream.Read(Byte[] buffer, Int32 offset, Int32 count)
     at System.IO.Compression.GZipStream.Read(Byte[] buffer, Int32 offset, Int32 count)
     at GitDependencies.Program.ExtractFilesFromRawStream(Stream RawStream, IncomingFile[] Files, SHA1 RawStreamHasher)Wrapped by CorruptPackFileException: Can't read from pack stream
     at GitDependencies.Program.ExtractFilesFromRawStream(Stream RawStream, IncomingFile[] Files, SHA1 RawStreamHasher)
     at GitDependencies.Program.ExtractFiles(Stream InputStream, IncomingFile[] Files)
     at GitDependencies.Program.DownloadAndExtractFiles(String Url, Uri Proxy, String CacheFileName, Int64 CompressedSize, String ExpectedHash, IncomingFile[] Files, Double HttpTimeoutMultiplier, NotifyReadDelegate NotifyRead)Wrapped by AggregateException: One or more errors occurred. (Can't read from pack stream)
     at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
     at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
     at GitDependencies.Program.DownloadWorker(ConcurrentQueue`1 DownloadQueue, AsyncDownloadState State, Double HttpTimeoutMultiplier, Int32 MaxRetries, CancellationToken CancellationToken)
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This is completely unprecedented. Your first ETA was same-day, now we have no ETA, and we still can’t build specific branches? What gives!?!

This has completely stalled my development workflow, making it IMPOSSIBLE to make an engine source build.

Considering that most if not all of the users who compile their own from source are either AAA game developers, professional programmers or need access to the source in order to tailor it to specific needs they are actually costing us money every minute they scratch their head on this issue. I think we deserve more respect than what we are getting here. I assume most who are getting it from Github are not your typical hobbyist or enthusiast. According to her last post it was already fixed. I see no evidence in that. Still cannot build the VS project files.

1 Like

Likewise, cant build tag 5.2.0-preview2 atm :confused:


So they have the 5.2 repositories uploaded now and that has the same issue? Thanks, saves me time cloning it.

Update only your /Engine/Build/Commit.gitdeps.xml and will work again.