Transaction error with Authorize.net in sandbox mode

Hi-

I am trying to use sandbox mode with Authorize.net and I keep getting this error code:

This is my form:

https://form.jotform.com/90073278140149

Thanks for your help!

I am sorry for the trouble caused to you. I did check your form and found that sandbox mode is not enabled in authorize.net payment tool. Please check the screenshot below:

Are you using authorize.net sandbox credential in payment tool or you are using live credential? I would suggest you to please enable sandbox mode and we will take a look.

We will wait for your response.

I had tried sandbox mode on/off as well as using the sandbox credential. Now I have sandbox mode on and I'm logged in using sandbox credentials. I don't get an error code, but the form does not submit. 

I was able to submit the form without any issue. Can you check again, and let us know if there's an error that popups on your end? 

When I click "Submit your donation," it flashes a small message at the bottom quickly, but then the message disappears and the page just stays. It doesn't submit, but I don't get an error. 

I figured out it's the Prefix dropdown that is causing the problem. I've fixed that for you. It's a required field, and you need to fill that up. It should suppose to show you the required indicator, but it is not doing that because your options are not configured correctly. 

I'm not sure how you were able to put a break tag in the area but looks like you've copy/pasted the texts. Well, I cannot replicate that either. Anyways, please let us know if the issue persists.