The error message is shown when you call NPrinting designer to edit any Office reports. It is possible to only click on OK, then, NPrinting Designer opens but the designer options to edit the template are not present.
It seems that the problem affects mainly Office 32 bit installations.
Environment:
- NPrinting 17 and NPrinting 18 all versions
The problem is due to incorrect registry keys versioning. It may happen if a later version of Office was installed on the same machine and then removed.
The solution requires some changes on the registry key of the machine where the problem occur. Be sure you have a backup of your registry before starting.
Follow these steps to resolve the problem.
1. Search for the key {0002096B-0000-0000-C000-000000000046} in HKEY_CLASSES_ROOT
2. Open the TypeLib subfolder
3. Notice the version and copy the registry key (see the image)

4. Go to HKEY_CLASSES_ROOT\TypeLib in the registry key
5. Search for the key you copied in point 3.
6. Remove all the folder version that are not equal to the version you copied in point 3. (see image)

7. Re-do all the previous steps for the key {9149349D-5A91-11CF-8700-00AA0060263B} and for the key {000208DA-0000-0000-C000-000000000046}.