Found this.

An error occurred processing a PUT request to http://xxxx/nuget/ks-nuget/: Synchronous operations are disallowed. Call ReadAsync or set AllowSynchronousIO to true instead.
 Details: System.InvalidOperationException: Synchronous operations are disallowed. Call ReadAsync or set AllowSynchronousIO to true instead.
at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpRequestStream.Read(Byte[] buffer, Int32 offset, Int32 count)
at Microsoft.AspNetCore.WebUtilities.FileBufferingReadStream.Read(Byte[] buffer, Int32 offset, Int32 count)
at System.IO.Stream.ReadByte()
at Inedo.IO.StreamSearcher.FindNext(Stream stream)
at Inedo.IO.StreamSearcher.FindAll(Stream stream)+MoveNext()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
at Inedo.Web.HttpRequestExtensions.GetPostedFilesInternal(HttpContext context)
at Inedo.Web.HttpRequestExtensions.GetPostedFiles(HttpContext context)
at Inedo.ProGet.WebApplication.FeedEndpoints.NuGet.NuGetApi.PutHandler.ProcessPutRequestAsync(HttpContext context, RequestData urlData, NuGetFeed feed) in C:\InedoAgent\BuildMasterTemp\192.168.44.60\Temp\_E55466\Src\ProGet.WebApplication\FeedEndpoints\NuGet\NuGetApi.PutHandler.cs:line 42
at Inedo.ProGet.WebApplication.FeedEndpoints.NuGet.NuGetApi.ProcessRequestAsync(HttpContext context, NuGetFeed feed, String relativeUrl) in C:\InedoAgent\BuildMasterTemp\192.168.44.60\Temp\_E55466\Src\ProGet.WebApplication\FeedEndpoints\NuGet\NuGetApi.cs:line 37
at Inedo.ProGet.WebApplication.FeedEndpoints.FeedEndpointHandler.FeedRequestHandler.ProcessRequestAsync(HttpContext context) in C:\InedoAgent\BuildMasterTemp\192.168.44.60\Temp\_E55466\Src\ProGet.WebApplication\FeedEndpoints\FeedEndpointHandler.cs:line 192

Hi,
Switched to progetcore due to a possible fix of DB timeouts. however found the following problem when trying to push packages via nuget.

[Exec] "C:\Txx\tools\NuGet.CommandLine.4.7.1\tools\Nuget.exe" push "C:\xxx.nupkg" -Source "https://xxxxxx/nuget/ks-nuget/" -ApiKey "xxxxxxxx"
[14:58:16][Exec] Pushing xxx.nupkg to 'https://xxxxxx/nuget/ks-nuget/'...
[14:58:16][Exec]   PUT https://xxxxxx/nuget/ks-nuget/
[14:58:16][Exec]   InternalServerError https://xxxxxx/nuget/ks-nuget/ 282ms
[14:58:16][Exec]   PUT https://xxxxxx/nuget/ks-nuget/
[14:58:17][Exec]   InternalServerError https://axxxxxx/nuget/ks-nuget/ 171ms
[14:58:17][Exec]   PUT https://xxxxxx/nuget/ks-nuget/
[14:58:17][Exec]   InternalServerError https://xxxxxx/nuget/ks-nuget/ 168ms
[14:58:17][Exec] Response status code does not indicate success: 500 (Internal Server Error).

Reverting back to the regular proget:5.3.10 works perfectly.

I havent tracked it, but i restarted container on Monday, by Tuesday morning when people returned to office/ started running builds, I started seeing Timeout errors. I will switch to the core version and see how that goes.

Hi I'm running 5.3.10 and getting timeouts again / max pool reached, is the database issue occurring again?

An error occurred in the web application: Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached.
 Details: URL: http://xxx/nuget/ks-nuget/v3/flatcontainer/xxx/xxx/xxxxx.nupkg
Referrer: (not set)
User: (unknown)
User Agent: NuGet Desktop MSBuild Task/5.5.0 (Microsoft Windows NT 10.0.18363.0)
Stack trace: at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection (System.Data.Common.DbConnection owningConnection, System.Threading.Tasks.TaskCompletionSource`1[TResult] retry, System.Data.Common.DbConnectionOptions userOptions, System.Data.ProviderBase.DbConnectionInternal oldConnection, System.Data.ProviderBase.DbConnectionInternal& connection) [0x0024d] in <0864334e7e474248b37afca9b637daa9>:0
at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal (System.Data.Common.DbConnection outerConnection, System.Data.ProviderBase.DbConnectionFactory connectionFactory, System.Threading.Tasks.TaskCompletionSource`1[TResult] retry, System.Data.Common.DbConnectionOptions userOptions) [0x00036] in <0864334e7e474248b37afca9b637daa9>:0
at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection (System.Data.Common.DbConnection outerConnection, System.Data.ProviderBase.DbConnectionFactory connectionFactory, System.Threading.Tasks.TaskCompletionSource`1[TResult] retry, System.Data.Common.DbConnectionOptions userOptions) [0x00000] in <0864334e7e474248b37afca9b637daa9>:0
at System.Data.SqlClient.SqlConnection.TryOpen (System.Threading.Tasks.TaskCompletionSource`1[TResult] retry) [0x0005d] in <0864334e7e474248b37afca9b637daa9>:0
at System.Data.SqlClient.SqlConnection.Open () [0x0003b] in <0864334e7e474248b37afca9b637daa9>:0
at Inedo.Data.SqlServerDatabaseContext.CreateConnection () [0x0006c] in <8a0468ee94a94ef1b2bba97871f29990>:0
at Inedo.Data.DatabaseContext.ExecuteInternal (System.String storedProcName, Inedo.Data.GenericDbParameter[] parameters) [0x00064] in <8a0468ee94a94ef1b2bba97871f29990>:0
at Inedo.Data.SqlServerDatabaseContext.ExecuteInternal (System.String storedProcName, Inedo.Data.GenericDbParameter[] parameters) [0x00005] in <8a0468ee94a94ef1b2bba97871f29990>:0
at Inedo.Data.DatabaseContext+<>c__DisplayClass29_0`1[TRow].<EnumerateTable>b__0 () [0x00000] in <8a0468ee94a94ef1b2bba97871f29990>:0
at Inedo.Data.StrongDataReader+<Read>d__11`1[TRow].MoveNext () [0x0003e] in <8a0468ee94a94ef1b2bba97871f29990>:0
at System.Linq.Enumerable.TryGetFirst[TSource] (System.Collections.Generic.IEnumerable`1[T] source, System.Boolean& found) [0x00045] in <22384ee444974b39bb55b725de39c721>:0
at System.Linq.Enumerable.FirstOrDefault[TSource] (System.Collections.Generic.IEnumerable`1[T] source) [0x00000] in <22384ee444974b39bb55b725de39c721>:0
at Inedo.ProGet.Data.DB+Context.Feeds_GetFeed (System.Nullable`1[T] Feed_Id, System.String Feed_Name) [0x0003d] in <888866fba54f44d68ecb60a2adf95719>:0
at Inedo.ProGet.Feeds.Feed.GetFeed (System.String feedName, Inedo.ProGet.Data.DB+Context externalDbContext) [0x0000b] in <888866fba54f44d68ecb60a2adf95719>:0
at Inedo.ProGet.WebApplication.FeedEndpoints.FeedEndpointHandler.GetHttpHandler (Inedo.Web.Handlers.GetHandlerParams args) [0x0017e] in <d560b10d729641519d596b0266d076a4>:0
at Inedo.Web.Handlers.DynamicHttpHandling.GetHandler (System.Web.HttpContext context, System.String requestType, System.String url, System.String pathTranslated) [0x0003b] in <8a0468ee94a94ef1b2bba97871f29990>:0
at Inedo.Web.InedoHttpModule.MapHandlerAndBeginRequestAsync (System.Web.HttpApplication app) [0x00029] in <8a0468ee94a94ef1b2bba97871f29990>:0
at Inedo.Web.InedoHttpModule.HandleBeginRequestInternalAsync (System.Web.HttpApplication app) [0x0000f] in <8a0468ee94a94ef1b2bba97871f29990>:0
at Inedo.Web.InedoHttpModule.ProcessBegin (System.Object sender, System.EventArgs e, System.AsyncCallback cb, System.Object extraData) [0x0000d] in <8a0468ee94a94ef1b2bba97871f29990>:0
at System.Web.HttpApplication+<RunHooks>d__217.MoveNext () [0x000a4] in <b4f0b153c02f4f0588d3f7549d75281b>:0
at System.Web.HttpApplication+<Pipeline>d__225.MoveNext () [0x0012c] in <b4f0b153c02f4f0588d3f7549d75281b>:0
at System.Web.HttpApplication.Tick () [0x00000] in <b4f0b153c02f4f0588d3f7549d75281b>:0

still looking forward to this in 5.3.11, but wanted to let you know release 5.3.10 had a fixed a bug that was caching unintentionally. Since these packages I do not intend to cache, the case sensitivity issue is not affecting me for now.

this is excellent news, i am looking forward to this fix.

thank you.

nuget version 4.7.1.5393

are there any other ideas to fix this?
new packages are going into the wrong folder and i have to copy it to the .Wpf one from .WPF
new package:

C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\Common7\IDE\CommonExtensions\Microsoft\NuGet\NuGet.targets(114, 5): The feed 'https://xxx/nuget/ks-nuget/v3/index.json [https://xxx/nuget/ks-nuget/v3/index.json]' lists package 'Syncfusion.Grid.WPF.18.2.0.54' but multiple attempts to download the nupkg have failed. The feed is either invalid or required packages were removed while the current operation was in progress. Verify the package exists on the feed and try again.
  Unable to find package 'Syncfusion.Grid.WPF.18.2.0.54'.

Running this command every time it breaks something cause a new package is not feasible.
Technically the package shouldnt be caching, so will PG-1804 fix this?

@atripp
So there is no trace from Proget side where it receives the request and see how it responds?

Also for the stacktrace @rhessinger mentioned should it be v2, when I'm using v3 ?

i completely agree that it shouldnt be using v2 api.. and i dont know why cause it is pointed to the v3 url.