GemFire Native Client throws "Error: Method implementation on an interface.....must be a final method."

Products

• VMware Tanzu Data Intelligence

Issue/Introduction

.Net Core applications connecting to Gemfire fail with the error below.

 

System.TypeLoadException
  HResult=0x80131522<app_name>
  Message=Method implementation on an interface 'Apache.Geode.Client.IRegion`2' from assembly 'VMware.GemFire, Version=10.4.7.4, Culture=neutral, PublicKeyToken=126e6338d9f55e0c' must be a final method.
  Source=GemFireNativeClient
  StackTrace:
   at GemFireNativeClient.<app_name>.<InitializeGemFire>d__7.MoveNext() in C:\<xxxx>\gemfire\GemFireNativeClient\<app_name>.cs:line 322
   at GemFireNativeClient.<app_name>.<InitializeGemFire>d__7.MoveNext() in C:\<xxxx>\gemfire\GemFireNativeClient\<app_name>.cs:line 322
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine)
   at GemFireNativeClient.<app_name>.InitializeGemFire() in C:\<xxxx>\gemfire\GemFireNativeClient\<app_name>.cs:line 276
   at GemFireNativeClient.<app_name>.<Main>d__4.MoveNext() in C:\<xxxx>\gemfire\GemFireNativeClient\<app_name>.cs:line 172

  This exception was originally thrown at this call stack:
    [External Code]
    GemFireNativeClient.<app_name>.Main(string[]) in 

 

Environment

Gemfire Server v10.1

Tanzu GemFire Native Client v10.4

Cause

This is caused by a mismatch of app framework and the native client libraries currently available.  As stated in the official documentation, client versions up to Tanzu GemFire Native Client v10.4 only support .Net Framework and not .Net Core.

 

Resolution

An upcoming release of Native Client will support .Net Core 8 and 10 for Gemfire Server versions of 10.2+. The tentative release is in Jan 2026.