The Install & Licensing Team uses the license parser every single day. For the most part, it works well. One of the basic rules of licensing is that if you are on Subscription for AutoCAD 2014, you don't need your AutoCAD 2013 license anymore. i.e Backup the file.
Please download the following sample files and load it in the license parser and then check out the contents using Notepad.
- AutoCAD 2013 license file on Subscription: AutoCAD-2013.lic
- AutoCAD 2014 license file on Subscription: AutoCAD-2014.lic
- AutoCAD 2013 + AutoCAD 2014 license file combined: AutoCAD-2013+AutoCAD-2014.lic
- AutoCAD 2014 + AutoCAD 2013 license file combined: AutoCAD-2014+AutoCAD-2013.lic
You will notice that when a license is combined (2013 + 2014 or vice versa), it will not read correctly.
1. Use only the current license file if possible.
2. You still need to look at the license file to double check it. I love using comments (#). The licensing tools ignores any line with a # in it.