Handle Multiple Documents

At the moment I decided to move forward using how to initialize the document this way: documentoValue []. Following the example File upload and download process example Another question arises me, in the second event called "Step upload new versions" in which you can delete documents already loaded previously and also to upload new documents, there is any way to do the same in that stage with other input fields? I tried the example only with documents and it worked, however I use in that form other fields to modify, but I indicates an error that is not how to solve.

I modified the code by adding the other input variables:
if(angular.isUndefined($data.formOutput) && angular.isDefined($data.context)) {
return {
"documentDelete": $data.context.document_ref,
'document': $data.formInput.document,
'date1': $data.formInput.date1, //Other variables
'date2': $data.formInput.date2,
'function': $data.formInput.function,
'coments' :$data.formInput.coments
};
} else {
return $data.formOutput;
}

The error is:
Error : { "exception": "class org.bonitasoft.engine.bpm.flownode.FlowNodeExecutionException", "message": "USERNAME=walter.bates | org.bonitasoft.engine.transaction.STransactionCommitException: bitronix.tm.internal.BitronixRollbackException: RuntimeException thrown during beforeCompletion cycle caused transaction rollback" }

I do not know if having multiple files and normal variables I have created a conflict. If someone to do what I try, I appreciate your help.
Regards,

Victor