Symptoms

After performing clean installation of K2 for SharePoint 4.6.10 (using latest installer version available at K2 portal - 4.13350.1720.2) you are getting an error when running K2 for SharePoint app registration wizard at SharePoint Service broker registration step:
“SmartObject Server Exception: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information”
Additionally for testing purposes you may try and register SharePoint 2013 service instance manually, using SmartObjects Services Tester tool – you will see the following error:
“SmartObject Server Exception. Could not load file or assembly ‘SourceCode.SmartObjects.Services.SharePoint, version 4.0.0.0’”
Note this last action can be used only to confirm this issue and you should never create or edit SharePoint 2013 service instances using tester tool.
 

Diagnoses

This is known issue with K2 for SharePoint 4.6.10 installer (4.13350.1720.2). It contains SharePoint Client Components 16.0.4002.1211 (sharepointclientcomponents_x64.msi), whereas K2 for SharePoint 4.6.10 requires version of 15.0.4481.1505 of SharePoint Client Components which was included in K2 for SharePoint 4.6.9 installer. This issue has been addressed in 4.6.11.
You will not be affected by this issue when performing upgrade from 4.6.9 our any other version which contained correct version of SharePoint Client Components.
 

Resolution

Install SharePoint Client Components 15.0.4481.1505 from K2 for SharePoint 4.6.9 installation package on K2 server. Installation package can be found in K2 for SharePoint 4.6.9 installation folder (InstallationRedistributablesharepointclientcomponents_x64.msi).