Hello,
I am sorry for the troubles. I fixed the problem and from now, you can create new threads in Resellers section. Same as in any other section. I also moved your post into a separate thread.
The problem you describe is probably caused by one of the following matters or both of them:
1. You have no subclient (contact) or subclient is not enabled in the module admin panel. Make sure that you have at least one subclient and it's enabled.
2. You haven't switched your template correctly. Make sure that you have followed the instructions located in the 'Integration Codes' section. More information you can find in our Wiki at point no.8:
http://www.docs.modulesgarden.com/Resellers_For_WHMCS#Installation