E00007 - Message using online testing tool

[PrintScan]

I'm using your online testing tool at

https://developer.authorize.net/api/reference/index.html

I put in my Login Id/Transaction Key - I click 'Done'. 

I go to Charge A Credit Card - I get 'E00007'.

I've recreated my transaction key a few times.  Still just E00007.

I've run a few C# samples, and that gives me E00007 as well.

Our account is in Test mode, but I swapped to Live a few times to see if that helped.
This is my second company to setup, and never had issues with that one.

Since this is the online test tool, this should be pretty simple fix.  What else should I look for?

[PrintScan]

This is still not working.  But when I switch to live mode, my C# sample does work.  Is there something I need to setup on my account to get sandbox to work?

I'm correctly switching

ApiOperationBase<ANetApiRequest, ANetApiResponse>.RunEnvironment = AuthorizeNet.Environment.SANDBOX;

to

ApiOperationBase<ANetApiRequest, ANetApiResponse>.RunEnvironment = AuthorizeNet.Environment.PRODUCTION;

[RichardH · Accepted solution]

@PrintScan

Are you attempting to use the same credentials for both production and sandbox?  If so, that won't work.  Each environment is completely separate and requires separate credentials.  

Richard

[PrintScan]

That is where I was failing.   I was thinking that all I had to do is switch from SANDBOX to LIVE.  I didn't realize that I have to use an entirely new userId/TransactionId.

Thanks for the response!