Assigment of particles to release zones

I run a simulation where particles where released in 24 zones along the Iberian coast. In the nc output file I found that for a huge number of particles a -1 code of release zone was assigned which correspond to "out of release zone". Do you have an ideia why this situation occur?
Thank you in advance for your help.
Henrique Cabral

Ichthyop version:

Hydrodynamic dataset: 

Java version:

Operating system:

Hi Henrique.

Indeed, there should be a problem, since particles should not be released until they belong to one zone. Do you have any error message or warning message ?

Could you please join your configuration files, including your release zones?