Hello Bearing,
When I try to customize the template, there are web calls to Rockettheme to check for latest template updates. Is there a way to prevent or workaround this so that I can continue to customize the website?
I want to double check something, does it prevent you from accessing the template manager completely? Can you still edit and save? The warning is intended for to be deisnged that way, although I can agree the warning message will be anoying. I believe the error is returned from Joomla. With more information we might be able to recommend a way to suppress the error. Also because the site is not connected to a network it is hard for us to recommend a proper solution.