Hi @rhessinger,

Sorry for the belated reply, we are running the pre release now and this solved the issues we were facing!

Thank you @rhessinger

If you could provide us with a pre-release so we can test the fix that would be great.

Unfortunately we still see the exact same behaviour:

with the following stacktrace

An error occurred in the web application: Unable to cast object of type 'Inedo.Extensions.Credentials.UsernamePasswordCredentials' to type 'Inedo.ProGet.FeedImporters.FeedImportService'.

URL: http://proget.***REDACTED***.services/feed/import/packages/importer?feedId=3&step=SelectSource
Referrer: https://proget.***REDACTED***.services/containers/registry?feedId=3
User: Admin
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36
IP Address: 10.13.151.55
Stack trace:    at Inedo.ProGet.WebApplication.Pages.Feeds.ImportWithImporterPage.<>c.<CreateChildControlsAsync>b__19_19(Credentials c) in C:\Users\builds\AppData\Local\Temp\InedoAgent\BuildMaster\192.168.44.60\Temp\_E645311\Src\src\ProGet\WebApplication\Pages\Feeds\ImportPackagesOfTheNewPage.cs:line 141
   at System.Linq.Enumerable.WhereSelectListIterator`2.MoveNext()
   at System.Linq.Enumerable.WhereEnumerableIterator`1.ToList()
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at Inedo.ProGet.WebApplication.Pages.Feeds.ImportWithImporterPage.<>c__DisplayClass19_0.<CreateChildControlsAsync>g__selectImportSource|1() in C:\Users\builds\AppData\Local\Temp\InedoAgent\BuildMaster\192.168.44.60\Temp\_E645311\Src\src\ProGet\WebApplication\Pages\Feeds\ImportPackagesOfTheNewPage.cs:line 139
   at Inedo.ProGet.WebApplication.Pages.Feeds.ImportWithImporterPage.CreateChildControlsAsync() in C:\Users\builds\AppData\Local\Temp\InedoAgent\BuildMaster\192.168.44.60\Temp\_E645311\Src\src\ProGet\WebApplication\Pages\Feeds\ImportPackagesOfTheNewPage.cs:line 81
   at Inedo.ProGet.WebApplication.Pages.ProGetSimplePage.InitializeAsync() in C:\Users\builds\AppData\Local\Temp\InedoAgent\BuildMaster\192.168.44.60\Temp\_E645311\Src\src\ProGet\WebApplication\Pages\ProGetSimplePage.cs:line 69
   at Inedo.Web.PageFree.SimplePageBase.ExecutePageLifeCycleAsync()
   at Inedo.Web.PageFree.SimplePageBase.ProcessRequestAsync(AhHttpContext context)
   at Inedo.Web.AhWebMiddleware.InvokeAsync(HttpContext context)

::Web Error on 03/09/2026 09:02:03::

@Dan_Woolf Thanks! I'll update you once we've installed the update

@Dan_Woolf
Here is a screenshot of that page:

When following the guide on how to setup Importing from Other Feeds/Servers we get a (500) Server Error.

We get this error after we click the button "Import packages" or "Download Package From Another Service" (the first when we do this with a Docker feed, the latter when we try to set it up for a Nuget feed).

The error message we see is: Unable to cast object of type Inedo.Extensions.Credentials.UsernamePasswordCredentials' to type 'Inedo.ProGet.FeedImporters.FeedImportService'.

Is this a known problem? Does anyone have a suggestion on how to fix it?
We face the same problem with both version 2025.21 and 2025.22
This is the complete stacktrace (redacted confidential information):

An error occurred in the web application: Unable to cast object of type 'Inedo.Extensions.Credentials.UsernamePasswordCredentials' to type 'Inedo.ProGet.FeedImporters.FeedImportService'.

URL: http://proget.***REDACTED***.services/feed/import/packages/importer?feedId=4
Referrer: https://proget.***REDACTED***.services/feed/import/packages?feedId=4
User: Admin
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36
IP Address: 10.13.201.75
Stack trace:    at Inedo.ProGet.WebApplication.Pages.Feeds.ImportWithImporterPage.<>c.<CreateChildControlsAsync>b__19_13(Credentials c) in C:\Users\builds\AppData\Local\Temp\InedoAgent\BuildMaster\192.168.44.60\Temp\_E641388\Src\src\ProGet\WebApplication\Pages\Feeds\ImportPackagesOfTheNewPage.cs:line 90
   at System.Linq.Enumerable.WhereSelectListIterator`2.MoveNext()
   at System.Linq.Enumerable.WhereEnumerableIterator`1.ToList()
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at Inedo.ProGet.WebApplication.Pages.Feeds.ImportWithImporterPage.<>c__DisplayClass19_0.<CreateChildControlsAsync>g__selectExistingSource|0() in C:\Users\builds\AppData\Local\Temp\InedoAgent\BuildMaster\192.168.44.60\Temp\_E641388\Src\src\ProGet\WebApplication\Pages\Feeds\ImportPackagesOfTheNewPage.cs:line 88
   at Inedo.ProGet.WebApplication.Pages.Feeds.ImportWithImporterPage.CreateChildControlsAsync() in C:\Users\builds\AppData\Local\Temp\InedoAgent\BuildMaster\192.168.44.60\Temp\_E641388\Src\src\ProGet\WebApplication\Pages\Feeds\ImportPackagesOfTheNewPage.cs:line 83
   at Inedo.ProGet.WebApplication.Pages.ProGetSimplePage.InitializeAsync() in C:\Users\builds\AppData\Local\Temp\InedoAgent\BuildMaster\192.168.44.60\Temp\_E641388\Src\src\ProGet\WebApplication\Pages\ProGetSimplePage.cs:line 69
   at Inedo.Web.PageFree.SimplePageBase.ExecutePageLifeCycleAsync()
   at Inedo.Web.PageFree.SimplePageBase.ProcessRequestAsync(AhHttpContext context)
   at Inedo.Web.AhWebMiddleware.InvokeAsync(HttpContext context)

::Web Error on 03/03/2026 17:20:32::