Error Message:
Error while creating new document. Error message: Error calling merge service. Error: Error: Exception: Element does not contain the specified child element. \tat MergeValuesService (RSDocuments v3:04)…

-This error message can happen for one of the following reasons:
1) Need to merge sure the child object related list item is merged into a table so the rows will be repeated.
2) If you uploaded your google doc template from a word document, there may be some hidden formatting inside the template causing this error message. Suggest to start with a fresh blank google doc and then copy/paste onto the template from the word document. That way you can be sure there is no hidden formatting.
3) Can happen when generating a document that does not contain the proper child relationship or you are trying to merge from mutliple child objects in one table.

How to resolve #3:
-You need to place different child object related list items in their own table which can still be inside the same table (just insert a table into the part of table the field already is then paste the merge field in it’s own small table). You can also white out the borders of that additional table so it doesn’t look like a separate table. Your other option would be to separate the child object related lists into their very own table separate from the other section where it is just merging fields directly from parent object.