Symptoms

User is running the Registration Wizard from App Catalog on K2 4.7, and gets a "Responsenull" errror during the Application step.

Diagnosis

 If, in the SmartObject logs, this is erroring on the following:

brokerpackagein

<brokerpackage><smartobject name="SharePoint_Integration_Workflow_Helper_Methods" guid="f343a8d0-c7c6-4ad1-b72d-07ed5b568c46" version="1" resultname="Primary_f343a8d0-c7c6-4ad1-b72d-07ed5b568c46_f343a8d0-c7c6-4ad1-b72d-07ed5b568c46"><property name="k2_Int_Resource_Guid"><value>scnull</value></property><property name="SpSiteUrl"><value> lSOME_SP_SITE_ULR] name="SPSiteName"><value>Available Apps</value></property><property name="IsOnlineSite"><value>false</value></property><method name="ManageSPLabelGroupProvider" /></smartobject></brokerpackage>

brokerpackageout

<brokerpackage><brokerpackage><result successful="false"><serviceinstances><serviceinstance name="SharePointIntegration" guid="f343a8d0-c7c6-4ad1-b72d-07ed5b568c46"><messages><message severity="Error">Responsenull.</message></messages></serviceinstance></serviceinstances></result></brokerpackage></brokerpackage>

Then this is most likely due to Group Providers. 

On the "Application" step of the Registration Wizard, we are going out to find all of the Group Providers, trying to pull back information for all of our SP sites. But in the event SP sites were deleted or servers get decomissioned, all of the group provider URLs became unavailable.  Hence, the error message. 

Solution

Please check in K2 Management -> User -> SP to look at SharePoint Group Providers. 

1. Make sure there are no duplicate Group Providers

2. Make sure you can navigate to all URLS. Test all Group Provider URLs BEFORE deleting them to insure those are not in use. After confirming nothing is on these sites, go ahead and delete Group Provider. 

After deleting Group Providers, go through and re-run the Registration Wizard.