Target input file not working

[Elisabetta Parozzi]

Dear community,

I have a target file generated with FLUKA  in root format and I want to use it as input file as beam. I've already done this multiple times with other files and it always worked smoothly.

With this new file I get the following error and I cannot interpret it:

I'm unsure what the "Multiple signals received (11,11)," means.

If someone could please help me.

I'm attaching here a small fragment of the root file I'm using.

Cheers,

Elisabetta