Npm registry returns 500 ArgumentException: Value cannot be null.Parameter name: stream

[Guest]

We get the following error on our npmn feed since upgrading to 5.0.x.

{"error":"ArgumentNullException","reason":"Value cannot be null.\r\nParameter name: stream"}

Logged error:

System.ArgumentNullException: Value cannot be null.
Parameter name: stream
at Inedo.Web.Handlers.HttpResponseExtensions.<TransmitStreamAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Inedo.ProGet.WebApplication.FeedEndpoints.Npm.NpmPackageDownloadHandler.<TryProcessRequestAsync>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Inedo.ProGet.WebApplication.FeedEndpoints.Npm.NpmHandler.<ProcessRequestAsync>d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Inedo.ProGet.WebApplication.FeedEndpoints.FeedEndpointHandler.FeedRequestHandler.<ProcessRequestAsync>d__8.MoveNext()

Product: ProGet
Version: 5.0.8

[Guest]

Republish packages fixes the error.

[Guest]

Because of a reinstall of proget with an existing database the package paths were resetted to default.

After fixing the paths, the error went away.
The error should be more descriptive when the files can't be found on file store.