three20 datasource and table issue

Why am I getting the following error:

*** Assertion failure in -[TTTableView _createPreparedCellForGlobalRow:withIndexPath:], /SourceCache/UIKit_Sim/UIKit-1448.89/UITableView.m:5678
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'UITableView dataSource must return a cell from tableView:cellForRowAtIndexPath:'
*** Call stack at first throw:

How do I fix this?

the point where it stops is:

- (void)layoutSubviews {
  [super layoutSubviews]; //right here开发者_如何学编程

this is inside TTTableView.m

'UITableView dataSource must return a cell from tableView:cellForRowAtIndexPath:'

There's your answer. You must be returning a cell. Either your datasource isn't set or tableView:cellForRowAtIndexPath: isn't returning anything.

I had the same issue when using RestKit + Three20 to populate a TTTableViewController with CoreData objects.

Turns out that the RKObjectManager's objectStore property wasn't set properly. I fixed it in the App initialization then the TTTableViewController was populated successfully.