It's not very clear from your message if GSX is REALLY "reverting to Trial mode", or it simply stopped working, because Couatl.exe has been blocked ( almost invariably by a faulty antivirus )
"Reverting to Trial" is a very specific situation, which manifests as follows:
GSX is working but, when you press the Hotkey, if you are NOT located on an FSDT airport or one of the 3 default Trial airports, you'll see a menu telling you GSX is in Trial, suggesting to go to a Trial airport. If you go to an FSDT airport or a Trial airport, GSX will otherwise work in full. THIS IS TRIAL.
This surely doesn't happen on its own, unless something very specific happens to your system, like changing major hardware components ( CPU or Mainboard or the Boot disk. Changing the video card or upgrading memory it's not enough ), or you reinstall Windows, or you switch to a different user profile, since your registry keys are stored in the user profile registry.
Also, it's not very clear what do you mean with "It does not recognise the .reg files". GSX is not supposed to "recognize" anything. Nothing in the GSX code ever reads or use the .REG files. .REG files are the STANDARD format to backup one or more registry keys, and their only function is to save you from MANUALLY typing your key, that's the only thing they do, and only after you double-click on them and accept the key to be inserted in the registry, which will prompt the Addon Manager to reactivate the key ( if it's not already active ) on the next startup, skipping the part where you have to type it manually. This is how a .REG file work in Windows, it's nothing we made up, it's a standard and, it's not really required to activate GSX, it's ONLY a time-saving feature that is alternative to manually typing the key.
If, instead, you already knew what .REG files are and how they work ( they don't do anything unless you double-click on them and accept the key to be inserted in the registry ), then I assume with "It does not recognise the .reg files", you really meant "It does not recognise my key", than it's an entirely whole different thing.
Of course, saying "it does not recognize my key", it's not helpful at all, since nowhere is the whole program code we have a "I don't recognize your key" message but, instead, we have many and very specific error messages, it would have been more helpful to know the *actual* error message instead.
A common one is the "activation key invalid" error, which usually appears because you might be using an old Esellerate key, which is one that starts with FSDT-xxxxxxxxxx.
In July 2019, due to the Esellerate closure, we had to switch to a different ecommerce system ( from Esellerate to MyCommerce, which are both run by Digital River ) and to a different activation provider ( from Esellerate to QLM/Soraco ). QLM/Soraco has been chosen very carefully, because they have a great feature that, while they normally issue their own keys, meaning new orders made after 2019 will use the QLM keys, their SDK and servers allows to also accept "Legacy Keys", meaning they are perfect to MIGRATE an existing user base from an activation method to another. This obviously required A LOT OF WORK on our part, because we had both to migrate all the orders from the past 10 years from Esellerate to QLM, and we also had to change our software to integrate the new QLM SDK, remove Esellerate and let it handle BOTH kind of keys.
When everything works as it's supposed to, this works perfectly because, you can use BOTH kind of keys without worrying which one is which so, old users could continue to use their keys, and new users would get new keys.
However, as usual, software conflicts gets in the way and, in order to work, this system REQUIRES a working connection to the activation server directly from Couatl.exe to the QLM server, one that is not blocked by a firewall or an antivirus. This because, the "Legacy" key is something known ONLY to the server. So, when nothing is blocking, the activation works as it always did, regardless if you use an old Esellerate key or a new QLM key ( the ones that starts with an "A" ). When something is blocking, the QLM License Wizard comes out automatically, because it has more features that enables it to pass through firewalls or proxies or antivirus. But the issue is, the QLM License Wizard doesn't know of the Esellerate keys so, BEFORE it connects to the server, it does a rough syntax check of the key you typed and, if it's not conforming to the QLM standard, it will say it's "invalid" before even checking on the server.
The simple solution in this case, is to use use a NEW QLM key because, for each past order made with Esellerate, a new QLM key has been associated to it. As I've said, when all works, you can use either, but when a firewall or antivirus is blocking the connection to QLM, and the License Wizard comes out, you MUST use the new QLM keys. Of course, in the FAQ page of our site, the procedure to retrieve a past order will direct you to the QLM Self-Help site which, starting from your email, will retrieve a list of all your past purchases, with their associated QLM key, even those that were originally made on Esellerate.
So, if you get the "activation key invalid" message, assuming you typed it correctly, the easiest solution is to use the QLM key instead of the Esellerate key, which work even with the QLM License Wizard, which comes out when a direct connection to the activation server cannot be established, usually because of a firewall or an antivirus.
