How do I get an SSRS subtable (tablixrow) to split across page breaks?

Question

I have inherited an SSRS report which is basically a single table (tablix), one row of which contains a subtable. When the subtable is less than 10 rows, the report fits on a single page. However, when there are more than 10 rows, the report inserts a page break before the subtable and starts a new page, leaving over half of the first page blank.

What the users would like is for the subtable to split across the page break; that is, have the first 10 rows on page one, then start page 2 with a header row for the subtable and continue it.

Is there a simple way to achieve this or is it a case where the report really needs rewriting from scratch?

FYI, we are using SSRS 2012.

Answer 1

In inner tablix make sure keep together on one page if possible is unchecked.

Other way you can handle is remove the inner tablix and incorporate the same functionality in the main table.

Answer 2

After further attempts, I managed to get the table to split. The problem was that the row did not contain only the tablix, but also had textboxes to either side. It seems these were kept together as a group.

FYI, the more interesting problem was getting the headers onto the 2nd and following pages in the sub-table. This MSDN article explained the use of advanced settings to achieve this.