As of SQL Server 2008 R2 the way to make headers of tablix’s repeat has changed considerably.
I suggest you read the post here:
In short all the documentation I found suggested you needed to turn on the “Advanced Mode”.
Advanced mode is a bit hard to find.
See the bottom of your design space you should see the heading:
Click on the static elements and it will highlight a cell in the report, this identifies the element you are attempting to change.
To make a heading repeat. Click on the static member for the header row/s of you tablix, view the properties pane and set these properties:
Edit – Nov 2011
So its been a year or so since I wrote this and in a case of dog fooding, I had to fix up a report and I hit the same error as listed by nes, itch and Terrence below.
Here is what the header Row Groups looked like in my report.
Each one of the static rows between “table1_eventId” and “rsvp” are rows in a group header in the report. When you click on the static row, the element in the report is highlighted
So I followed my own instructions and setup the row group properties on the static row immediately above rsvp as per my instructions, ran the report and got a similar error to Terrence.
Delving into the issue there are two possible solutions:
Assuming that you need all the header rows to repeat on each page, then you need to configure EVERY static row in the row groups in the same way, (every row between table1_EventId and Rsvp). Get one of the properties different and you get that error.
Assuming you don’t need the entire section above to repeat on every page. I needed to only have the table header row repeat. (the last static row prior to RSVP contained the details of the table column headers).
I right-clicked on the RSVP row Group, chose Insert Row –> outside Group – Above. This inserted a single blank row. Copy the header columns from the row that is now in the outer group, and paste into the new row that appeard. Delete the previous header row. Now follow the instructions above. As there is only 1 row then the repeating header instructions above will work.
Here is what the row groups looked like after solution 2. The static row between rsvp and table1_details_group is the header as highlighted and this is where you can setup the single repeat header proper
The trick is that to have the header repeat you have to update every row at a level in the row group to have the same settings.