Error message from Scala files with only one step

I am trying to make a scale file with only a repeating just third 5/4
and I get an error message when I try to load it into Pianoteq. With
scale size set to 1 I get "Error at line 4", with scale size set to 2
I get "Scala file is invalid - scale size is 1 instead of 2"?

I asked the creator of the Scala scale format about it, and he responded like this:

"When you only have one pitch, any other scale size than one is erroneous.
Therefore you should ask Pianoteq why the file doesn't load."

All the best,
Joakim