This article was created in response to a support issue logged with K2. The content may include typographical errors and may be revised at any time without notice This article is not considered official documentation for K2 software and is provided “as is” with no warranties.


When running the 'Manage App Activation' under the Administration section of K2 for SharePoint, the following error appeared:


The following error is present in the HostServer Logs:

"Error","General","0","ErrorMessage","IntegrationService.Execute","0 SourceCode.Hosting.Exceptions.APICommunicationException: Error Receiving Buffer:An established connection was aborted by the software in your host machine ---> System.Net.Sockets.SocketException: An established connection was aborted by the software in your host machine at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags) at SourceCode.Hosting.Client.BaseAPI.SocketBaseAPIConnection.OnReceiveBuffer(Byte[]& recvBuff) at SourceCode.Hosting.Client.BaseAPI.BaseAPIConnection.ReceiveData(ValueType& hd) 
--- End of inner exception stack trace ---

at SourceCode.Hosting.Client.BaseAPI.BaseAPIConnection.ReceiveData(ValueType& hd)

at SourceCode.Hosting.Client.BaseAPI.BaseAPIConnection.WindowsAuthentication(SCConnectionStringBuilder connectionStringBuilder)

at SourceCode.Hosting.Client.BaseAPI.BaseAPIConnection.Authenticate(String connectionString)

at SourceCode.Hosting.Client.BaseAPI.SocketBaseAPIConnection.OnOpen(SCConnectionStringBuilder connectionStringBuilder)

at SourceCode.Hosting.Client.BaseAPI.BaseAPIConnectionBroker.OnOpen(SCConnectionStringBuilder connectionStringBuilder)

at SourceCode.Hosting.Client.BaseAPI.BaseAPIConnection.Open(String connectionString)

at SourceCode.SmartObjects.Services.SharePoint.Integration.Execution.Execute.ManageSolutionDesignerServerRights(String siteUrl, String groupIds, Boolean removeUnspecified)

at SourceCode.SmartObjects.Services.SharePoint.Integration.Execution.Execute.ManageK2ApplicationSettings(ServiceInstance Service)

at SourceCode.SmartObjects.Services.SharePoint.Integration.IntegrationService.Execute(). Additional info: IntegrationService.Execute."


This could be as a result of a mismatch between the WorkflowServer Host name and the Host name received from the K2 Server.


To resolve this issue, complete the following steps:

1. Decrypt the K2HostServer.exe.config file

  • Stop the K2 Blackpearl server service
  • Backup the "K2HostServer.exe.config" file
  • Create a directory on the C:\ drive - "C:\Temp"
  • Make a copy of the "K2HostServer.exe.config" to "C:\Temp" directory
  • Rename the K2HostServer.exe.config in the "C:\Temp" directory it to "web.config"
  • Run Command Prompt in Administrator Mode
  • Run 'cd C:\Windows\Microsoft.NET\Framework64\v4.0.30319' to change directory to this framework version
  • Run 'aspnet_regiis.exe -pdf "connectionStrings" "C:\Temp"'
  • This command will decrypt the encrypted 'connnectionStrings' section

2. In the web.config file search for 'connectionStrings' and in the connectionStrings section search for 'WorkflowServer'

Please note that there are 2 'connectionStrings' sections, one of them are commented out

3. Change the Host from the fully qualified name to the PC name:

e.g. to Host=K2server

4. Rename the web.config file to 'K2HostServer.exe.config'

5. Copy the K2HostServer.exe.config to the following directory: '\K2 Blackpearl\Host Server\Bin'

6. Start the K2 Blackpearl Server Service.