validation on add

[paulwilhelm]

Hello, i have a problem with SC restDataSource

After an add operation i sometimes return the following JSON Struktur:

{response:{
status:-4,
errors:{tag1:{errorMessage:"Kollision"}}
}
}

and then i get the message:
"Server retuned VALIDATION_ERROR with no error message"

Can you please tell me what I did wrong.
Tahnks and kind regards Paul