In MYOB, you may get the error "Object variable or with block variable not set" when you select Mail Merge if you're using Microsoft Word. The error may happen if there's a timeout because Word is slow to start all components.
For example, if you try the Mail Merge when Word isn't already open, while it's opening, the Mail Merge routine may try to access Word components which aren't ready. If you select the Mail Merge again later, it may be able to continue without error because Word has had time to load.
Mail Merge without an error
Open Word before you select the Mail Merge or before you preview bills.
For compatible versions of Microsoft Office, see MYOB Compatibility with Microsoft products and technologies.