Error Trying to register Total Uninstall Pro

Hello,
I have been unsuccessfully trying to register Total Uninstall Pro several times now. I found that my Total uninstall has got unregistered when I had completed installing ESET. I took this to be an error caused by a change in my Firefall settings I tried to register after uninstalling ESET. But I was not allowed to register with a registration failed error message .Then I deleted the program rule manually from firewall and tried to register I got another error message which said ‘The order is not valid’. What is causing this error? Can anyone help me to register Total Unistall, please? Thanks in advance.

Registration failed.
The order is not valid.
