KB19930: "Object variable or With block variable not set" error when accessing advanced sorting after adding a grid that contains an object prompt in a Report Services Document 9.x

SYMPTOM:
When using a Report Services Document that has a dataset which contains an object prompt, advanced sorting is inaccessible after adding the grid in the document, due to the error displayed below:
 
`DSSRepSortsLib`
`Object variable or With block variable not set.`
 
STEPS TO REPRODUCE:
In tutorial,
 

1. Create a Report with 2 attributes in the rows along with one attribute object prompt and metric in the columns.
2. Save the report and use it a dataset for a Report Services Document.
3. Drag the dataset to the detail header section. Note: The object prompt will not appear due to another known issue(KB5700-75x-1371).
4. Double Click the grid to place it into edit mode.
5. Go to the 'Data' menu and click 'Advanced Sorting'.

CAUSE:
This is a known issue in Strategy Report Services Document 9.x.
 
ACTION:
Strategy will continue to investigate and post updates as soon as they are available.
 
WORKAROUND:

1. To workaround the issue, perform the following steps:
2. Save the report without the attribute object prompt.
3. Re-add the dataset grid to the Report Services Document.
4. Open the document and then use the Advanced Sorting dialog.
5. Go back to the dataset report again and re-add the attribute object prompt onto the template.

NOTE
After the object prompt is re-added to the dataset, the Advanced Sorting dialog box will no longer be accessible.