I tried to log in, and a message like this appeared "You are ineligible to use this product or service due to the Service Eligibility Requirements" what is the cause?

Hi ​@Neethan 

Hope you are doing well and sorry for the trouble.

This error usually means your Adobe ID lacks required info (like date of birth), detects an under-age/restricted region, or has licensing conflicts. Please check the steps shared in the help page https://helpx.adobe.com/creative-cloud/kb/you-eligible-cc.html and see if that works. 

~Amal