Issue

After successfully running the AppDeployment Installer to add the K2 for SharePoint App to a SharePoint 2016 AppCatalog Site, the K2 for SharePoint App is visible in the AppCatalog under “Apps for SharePoint”. But then when trying to add the App from Site Contents, the K2 for SharePoint App is not displayed.

Symptoms

After accessing the "Site Contents" page on the AppCatalog site, the K2 for SharePoint App is not displayed.

The following error is also observer in the SharePoint 2016 ULS logs:

An exception was thrown while retrieving Apps from Corporate Catalog. Microsoft.SharePoint.SPException: One or more field types are not installed properly. Go to the list settings page to delete these fields. ---> System.Runtime.InteropServices.COMException: One or more field types are not installed properly. Go to the list settings page to delete these fields. 

Resolution

For SharePoint 2016 there are both a “language dependent fix” and a separate “language independent fix.”

The issue occurs if one of these SharePoint Cumulative Updates are installed without installing the other.

From the official SharePoint Cumulative Update page:

It is required to install both fixes (language dependent and independent) to fully patch a SharePoint server as each SharePoint installation comes with a language independent component and a language dependent component. If additional language packs are added later (only) the language dependent fix has to be applied again.

At time of writing (March 2018), the SharePoint Cumulative Updates are available via the following Microsoft Articles:

Latest Language Independent CU: February 2018 CU for SharePoint Server 2016

Latest Language Dependant CU: January 2018 CU for SharePoint Server 2016