There is a bug on line 17427 of ext-all-debug.js in the function updateIndexes of the DataView object.
The line reads:
When the endIndex value passed to the function is equal to 0 (i.e. when there is only one item in the view) this line results in endIndex being the boolean value 'true'. The subsequent lines then try to do a for loop from 0 to true, with true being interpreted as 1, which results in an error (ns[i] has no properties) as there is no element at index 1 in the array it is operating on.
endIndex = (endIndex || endIndex === 0) || (ns.length - 1);
To correct this the line should just be changed to read:
endIndex = (endIndex || endIndex === 0 ? endIndex : ns.length - 1);