400 - ___arguments is not defined

I keep getting this error, although everything in my app seems fine and it works perfectly when testing and previewing it, however when invoking it, i get a 400-___arguents is not defined error.

where do i start looking for the fault?


Hi Rickus,

Could you please describe how we can reproduce the problem?


Hi Mark
Thank you soo much. it will be very helpful if you could guide me as to where i should start looking for my error.

it works perfectly fine when testing and previewing it. i get all the information like i want it and how i want it. However as soon as i invoke the settings, i get the “400-___arguents is not defined” error. everything in logic seems fine as far as my knowledge goes.


Hello @Rickus_vd_Berg

It Seems like you copy/paste your client logic from the UI-Builder to your BusinessLogic, they both have a different environment for running code and it won’t work.

What should Form1 Data refer to on this screenshot?

Regards, Vlad

“Form1 Data” represents all the information on my app form which is completed by the user. Once the user hits “submit” button, all that info are sent to my email.

but this is not a UI-Builder app, this is Business Logic (Cloud Code) which is running on the server https://backendless.com/docs/codeless/codeless_what_is_a_codeless_api_service.html

ok thank you. so what should i then do now? can you maybe give me a guideline to how my logic should be coded?


The support team can assist you with questions for how specific APIs or UI elements work. However, assistance with implementations is what our professional services team does. If you would like us to help you with it, please contact us at sales@backendless.com.