To recap: EasyGerb has been working fine from 2019 (until just last week). EasyGerb software has not changed. I have researched your subscription activation code - everything checks out fine and we have not turned off or deactivated your license.
Why was there a problem with AutoCAD 2016 and EasyGerb not working last week (this is the primary issue)?
Note: When you switched AutoCAD 2018, I am almost positive you were just using the free 5-day demo (and saw the demo message each time stating demo will expire soon). AutoCAD 2018 was only working because you it was using the free demo license - and not the subscription license.
Sorry for so many questions (see below), but there has to be something different (on your computer) which is preventing EasyGerb from running as before.
Suggestion #1: Here's our Help Center with many related topics, https://support.numericalinnovations.com/support/search/topics?term=easygerb+cloud
Suggestion #2: Try downloading and installing the newest FAB 3000 and EasyGerb from our website.
Suggestion #3: Lastly if EasyGerb problems persist, try using either FAB 3000 or ACE 3000 (which are included with Numerical Cloud). Both can convert your AutoCAD DWG files to Gerber (just like EasyGerb), https://www.numericalinnovations.com/pages/dxf-dwg-conversion-secrets-for-gerber-gds-ii-odb-etc
Tuesday I got 1 design from customer. But I could not open auto cad 2016.
So I open it in 2018, after I finished the job , I continue convert to gerber in side 2018.
But they ask activate code, I think auto cad 2016 & 2018 can use the same code.
So I do the same like before I activated 2016. But it did not work in 2018.
Therefore, I go back to 2016 to Gerb this job, but didn’t work any more .
That what happened. I think may be that the reason.
Can you help.
And I think next month, we have 1 more person work, and when we build the new computer, we need install new software.
What new version you have in Easy gerb & Fab 3000.