Generally there's a very easy fix for when you get the message "Error creating license file." First, depending whether you are on Mac or Windows, go to either of the folders listed below:
Mac: ~/Library/Application Support/
Then look through the resulting directory, find the folder named “Plugin Alliance” and throw it away.
If you continue getting the same message, or if you didn't find a folder named “Plugin Alliance” in that directory above, there is probably a permissions issue with the directory where the license file goes. In that case, you can right-click on the Application Support folder, select "Get Info" and try changing permission settings, or you could try getting help from Apple Support. But the simplest solution would probably be to just create a USB stick licensor. Then the license will be on your USB drive instead of your internal hard drive. Here's how to do that:
To authorize a USB thumb drive, make sure you usb drive is in your computer. Then, open one of your plugins in ProTools (or any host) and click on the "Activation Required" text, or the key icon on the bottom right side of the plugin window. An authorization window will pop up. Under the text "Select the device you would like to activate" there is a pulldown menu. Click it and select your USB drive. Then click "I'm Online" and enter your login info, and click "Activate." Now your USB drive is authorized and can be used on any computer.