Sorry, it was a bug of 3.1, you cannot have an empty field
in a line
use 0 0 or something like that or change the model
note that if you were to say:
SomeClass : "name"
MyTag "" "" "I only want to store text"
and later
SomeClass : "name"
MyTag 1 2
then "I only want to store text"
would be lost anyway
so the model is ackward