Symptoms

We can't create package via K2 Package and Deployment. An error message is shown "Index was out of range. Must be non-negative and less than the size of the collection. Parameter name:index"
 

Diagnoses

- User attempt to add entire category when creating a package

- That entire category contains a large number of items

- Error appears when too many items are included in the package

- Error did not appear if we only select to add a form and its dependencies
 

Resolution

Split up your package. Do not include the entire category into the package. Only add the items you have modified along with its dependencies.