Invalid data: The receiving plugin may not be activated at:

Hi,

For some time, I'm trying to install this plugin, but does not work correctly.

I follow all instrucctions, but when I try to create a site with WHMCS, always show this error "Invalid data: The receiving plugin may not be activated at:..."

The blog is created in the WordPress Multisite installation through WHMCS but is not activated in WHMCS (show that error)

Then;

If I try to create the site again from WHMCS, WHMCS say: "Site already exists.:" (logic)
If I try to Suspend the site, WHMCS say: ": domain not found when trying to suspend:[] [0]" (If I try to create again the site, WHMCS find the site, but if I want to suspend it, WHMCS dont fint it Why?)
If I try to Terminate the site, WHMCS say: ": domain not found when trying to terminate:[] [0]" (same as Suspend)

In WordPress Multisite plugin settings, in "Remote WHMCS host:" what I have to type (My WHMCS installation in in subdomain and subdirectory)

- http://whmcs.domain.com/subdirectory
- http://whmcs.domain.com/subdirectory/
- whmcs.domain.com/subdirectory
- whmcs.domain.com/subdirectory/

Any idea about the issue?

Thank you