The AIMMS Google Groups is still available.
You can no longer start new topics there, but you can still search for information and answers.
If you want to start a new topic or ask a new question, you can do that here on the community.
to go to the Google Group.
And click here
to ask a question related to AIMMS Developer, here
if you have a question about AIMMS PRO (or the AIMMS Cloud Platform), here
you go to ask for WebUI and if you want to go to the SC Navigator forum then click here