Express checkout redirect works on my computer, but get an internal error (500) on website

[zoli_wekingz]

Express checkout redirect works with wampserver on my local computer, but I get an internal error on website (sample code is same on both).

I cleared browser cache, restarted the browser(s) and computer, etc.

I tried with sandbox and live account too, but it doesn't matter, still getting internal error (500).

Security (redirect) settings may be the reason, or what?

[snowshoe]

As the scope of this forum is a bit less technical, here's two alternative options to see assistance.

Tech Support:

https://ppmts.custhelp.com/app/home

Developer's Forum:

http://stackoverflow.com/questions/tagged/paypal