I have a TabPanel with a grid at the first tab. When double clicking a record a new tab opens with a form on it where the user can edit or erase the record.

When the user wants to erase the record, scrolling the grid causes an exception and only a subset of the records are shown.

Exception:

Ext.util.Collection.getRange(): Inverted range passed to Collection.getRange: [Infinity, <number of remaining records in store>]

Fiddle (use developer console for exception): http://ift.tt/1IY6CEL

I think, the problem is, that the grid is not active, when the script tries to calculate the first visible record.