# What Expiration Means _Reviewed July 2020_ One of the key data elements of the software license and key is the "maint. expir." date. The "maintenance expiration" date works like this: • Regardless of the expiration date, A-Shell will run properly; the maintenance expiration date has nothing to do with the normal _running_ of A-Shell. A-Shell will keep running forever, regardless of the maintenance expiration date—unless you try to update, as explained in the following notes. • The expiration date has only to do with your ability to _update_ A-Shell. • As long as the expiration date has not passed—i.e., your software maintenance is "current"—there are no restrictions or limitations on your ability to update A-Shell. • When the expiration date is in the past, then your ability to update is limited. The general rule is: don't update A-Shell if the maintenance expiration date is in the past. More specifically, here is how that works: • When A-Shell runs, it checks its own release date against the maintenance expiration date. If the A-Shell date is newer than the expiration date, then A-Shell will run, but it judges the software license to be invalid. An invalid license means that A-Shell will operate only in demo mode, which in turn means that only one user is permitted and annoying "nag" messages appear frequently. • Note that the comparison of the A-Shell date and the expiration date do not involve _today's_ date. In other words, it doesn't matter when you perform the update; what matters are the dates of A-shell and the expiration date. **Practical Concerns** I just got a new A-Shell license. Must I install it? No. You _should_ install it, so that when you check the status of your A-Shell license, it shows the same date as your most recent authorized license. However, you don't _need_ to install it unless/until you are planning to update your A-Shell software. My license has a maintenance expiration date of 15 October 2019. Can I install the latest update? No. The latest version of A-Shell is more recent that 15 October 2019. Therefore, if you install that update, the date of the A-Shell program will be more recent than your expiration date, and A-Shell will revert to demo mode. My license has a maintenance expiration date of 15 October 2019. What version of A-Shell can I install? Anything with a release date before 15 October 2019. Check the [A-Shell History documentation](https://www.microsabio.net/dist/doc/hist/00hist.htm), and determine what is the newest version of A-Shell that was released before 15 October 2019. You can install that version of A-Shell, or any one that is older. I accidentally updated A-Shell to a version that's newer than my license, and I'm now able to run only in demo mode. What do I do? [Contact MicroSabio](https://microsabio.com/contact-2/) or the firm from which you bought A-Shell, and get an updated license. Once you install the new license, with an expiration date in the future, A-Shell will run in licensed mode. If you are unable or unwilling to install an updated license, then you can try installing an older version of A-Shell. Check the [A-Shell History documentation](https://www.microsabio.net/dist/doc/hist/00hist.htm), and install a version of A-Shell with a release date before the maintenance expiration date on your license. How to I check the maintenance expiration date? Get to the A-Shell prompt and enter [LICENS](licens.md) or [ABOUT](about.md). In A-Shell/Windows, you can also check _Help...About_ on the menu bar.