Important noted: SaaS 2.0 using Let’s Encrypt for SSL it totally free, but Let’s Encrypt have a rule for generating SSL key limits, so it cannot generate too many SSL keys at the same time, your system will fail to generate Odoo App instance.

for more info, plz visits here:

Odoo SaaS 2.0 Fail generate client

Odoo SaaS 2.0 Fail to generate client