image batch processor does not work on file name

[Dirk Funhoff]

Dear all,

I very seldom use the image processor to insert a specific category into the filename. It worked but not anymore. Unfortunately I cannot tell when it stopped working. I use this command
{File.Categories.Direct|filter:Naturfotografie - Arten;level:leaf}_{n}
The result is just _{n}.

What do I do wrong? 
Thanks for helping me out,
all the best, Dirk

[Mario]

Did you check your variable in the VarToy app to see what it returns?
Does it produce what you think it produces? Looks like the category result is empty?

[Dirk Funhoff]

Many thanks for the quick and helpful reply. Turned out to be 2 spaces too much, VarToy helped to run it down.
Have a nice evening,
Dirk

[Mario]

Very good.
The VarToy is great for debugging issues with complex variables. I use it very often.