When given a license code to apply to your Solver Platform installation, open the attached or linked text file and copy then ENTIRE contents of the file. This(picture) for example, contains license codes for Analytic Solver Platform and our Large Scale Engine package.
Once the contents are copied(right-click or Ctrl+C) then proceed to open Excel and our Solver Platform tab to enter in the code(Solver Platform tab-Help-License Code).
From here, paste in the license contents in the bottom license code entry box while leaving the top Activation Code empty. Don't worry if the license code looks cut off. It should be in there assuming whatever you copied is now pasted.
After applying the code and hitting OK, the Solver should have the license set. You can verify this by going to 'Help-Change Product' which list the products and their days remaining as shown above. Make sure you check the box that has the product you desire.
If license problems arise(it keeps asking for an activation/license code), try these advanced license folder edits to allow for multi-user use found here.