Many corporate networks block traffic to all websites by default unless they have been specifically granted access. This is especially true in server environments.
If you are having licensing issues with SimpleIndex not having access/permission through the internet to activate the software online then this access needs to be granted by your corporate IT network managers.
This is the specific website URL that the activation server must access:
You can just grant access to the full SimpleIndex.com domain as well.
For concurrent licenses it is necessary for the machine to be able to activate online. For workstation licenses you can work around this by doing a one-time Offline Activation instead. To do this click the Offline Activation button on the Activation screen and follow the instructions in the dialog box.