1 . Proxy is not used for Internet access, however, when we try to activate RAS, it prompts to configure Proxy. Activation has been working previously without any issues.
The IP address of ras.parallels.com eventually got blocked by the firewall.
2 . You are unable to access your Personal or Business Account on parallels.com:
The IP address of account.parallels.com is blocked.
NOTE: For new interface my.parallels.com should be also accessible.
3 . You can access your account at account.parallels.com but you can't open a page from Menu > Subscriptions and Licenses > Corporate Subscriptions
The IP address of license.parallels.com is blocked.
4. System Report could not be uploaded to Parallels or report number is empty.
The IP address of report.parallels.com is blocked.
5. When accessing Parallels Account, it prompts to confirm browser, however confirmation email never arrives to your mailbox.
The IP address of s.parallels.com is blocked.
NOTE: It is not necessary to allow absolutely all traffic. Only HTTPS is quite enough. It is recommended using DNS names for firewall rules configuration as IP addresses might be changed in future.