Hello,
thank you for feedback. And you are right, in a way. If you know that this can happen, you can check it right away, without having to wait for 30 minutes - see

opclabs.doc-that.com/files/onlinedocs/QuickOpc/Latest/User%2...0Obtain%20serial%20number.html

If the serial number (in your case, after the registration) comes out as 111111xxx, the effective license being used is a trial/demo license.

But, of course, if you do not explicitly check for it, you would not know. I understand your point, will think about it, and will see if it can be improved. Refusing to run altogether was an option we considered, but believe me, in other scenarios users would not like it either.

Re

"And a reason for rejection of the license should be given."

: In latest version, the exception after the allowed run-time lists a "dropped license" serial number. and the last covered released date. So this part is already resolved.

Re

"How can us users know what versions the license is valid for?"

: In the License Manager (or via the code), you can view the "Release date covered" field - again, assuming that you actually know about it and actively check it.

Thanks for the feedback again
Best regards

Hello.
The behavior is correct.

You have purchased a license without an upgrade assurance. This means that it covers the version that was current at the time of purchase, and any version released in 60 days following that.

QuickOPC versions, together with their release dates, are here: kb.opclabs.com/Versions

You need a version upgrade in order to be able to use newer versions.

Best regards