My license key does not work - common causes
As some customers recently received new license keys, I received some questions why their new license does not seem to work, other than the expiration date being reached. So far I was able to solve all of them with this short list of things to look at.
1. Is the date on your laptop set properly?
2. For Europe (and possibly other regions): the expiration date in the cache.key file is in US format, MM/DD/YYY, while most people there are used to DD/MM/YYY. This is obvious if you have an expiration date like 11/30/2016, but not with dates like 3/12/2016 (expires in March, not December).
3. Check the location of your Cache installation. Sometimes there is a leftover folder structure from inactive or uninstalled versions of Cache, which do contain an MGR folder. You need to put the cache.key in the MGR folder of your active installation.
4. Check if your key matches the platform which your working on. Keys can be platform independent, which shows as plain text in the cache.key file (Platform Independent). Beware that 32 and 64 bits of the "same" OS are considered different platforms, so if your key states "x86 - 32 bit (Windows)" it will not work on your brand-new laptop with Windows 10 64-bit preinstalled.
5. You opened your cache.key (which is a text file) in an editor, and accidently saved it which caused in to be stored in a slightly different format (other encoding and/or it now contains control characters). If you open it, it still looks like the original key visually, but it still doesn't work. Find the original cache.key, which you probably received in a mail message and use that one. If you want to look at it with a text editor that's OK, but don't save it.
If you have other tips, please add them as a comment!