Group type returns error

[jmcan]

When using the group type I get an error on the number of values in the column.

E.g. from the example given in the documentation, this message is returned:
Error: Column 2 had 7 while previous column had 2

So it seems like the nested values are treated as a single value column and therefore it thinks the column has 7 rows, when it in reality has two.

[janrueckert]

+1