I upgraded to 17.12.3 and got a weird error about “DiscoverPrecompressedAssets” task failed unexpectedly. Did not have this issue before upgrading.

[vsfeedback]

This issue has been moved from a ticket on Developer Community.

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[severity:I'm unable to use this version] [regression] [worked-in:17.12.3]
The "DiscoverPrecompressedAssets" task failed unexpectedly.
System.ArgumentException: An item with the same key has already been added.
at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
at System.Collections.Generic.Dictionary2.Insert(TKey key, TValue value, Boolean add) at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable1 source, Func2 keySelector, Func2 elementSelector, IEqualityComparer`1 comparer)
at Microsoft.AspNetCore.StaticWebAssets.Tasks.DiscoverPrecompressedAssets.Execute()
at Microsoft.Build.BackEnd.TaskExecutionHost.Execute()
at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext()

Got this error in my Microsoft.NET.Sdk.StaticWebAssets.Compression.targets file. I do not know how to fix and will be reverting to older version

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Original Comments

Emily Gabbard on 12/3/2024, 10:54 PM:

(private comment, text removed)

Feedback Bot on 12/4/2024, 06:34 AM:

We have directed your feedback to the appropriate engineering team for further evaluation. The team will review the feedback and notify you about the next steps.

Mike Rahel on 12/9/2024, 11:54 PM:

I am also experiencing this once I have upgraded to 17.12.3. Please let us know how to resolve. Thanks!

[wadebaird]

I am hitting this same issue, I can't provide a repro as it's occurring in my test project, which I can't share the code, and due to the vague error, have no clue what the issue is to give a repro on.

[wadebaird]

Would the project file contents be helpful? I'm not sure what the source of this error is.

[davinfifield]

Is there a workaround for this? Seems to be blocking me from building a brand new AspNet Core project.

[davinfifield]

I tried falling back to .NET Framework 8, thinking that might solve the problem, but same issue still exists.