Resolving checkout "SyntaxError: Unexpected " errors

If you ever see an error similar to:

SyntaxError: Unexpected Token
SyntaxError: Unexpected Character
SyntaxError: JSON.parse: unexpected character
Or if you click the Continue button but it never goes to the next step...

Common reasons for this:
- Not all files were uploaded for a mod or extension
- You are using a mod that came with a language file that is different than your current language, but haven't cloned the language file into your language folder
- Actual bugs in the code

This video will show you how to track down the issue.

In the video, I am using Google Chrome as my browser and the "Firebug Lite" addon.
You can do something similar with Firefox and the "Firebug" extension if you are more familiar with that.

http://screencast.com/t/SrBr64JUZu

So you can see in this video example, the error shows that it could not load the language file for worldpayxml. That means the file was not uploaded to the server or doesn't exist in your language so be sure to upload the files or copy the files from the default language to your language.

If you don't understand what the error means, copy the error from firebug lite and paste the actual error on the forums.

I have figured out how to show the real error in the popup message now. Now it will show the full error instead of just "Syntax Error" making this process much easier for all.

Starting with 1.5.2 and later this will already be included in the core. Use this patch with 1.5.0 to 1.5.1.3 only.

You can add this patch now from here:
http://forum.opencart.com/viewtopic.php?f=133&t=45863