Adobe muse 2018.0 version problem.

i started to work on a template in a new version of adobe muse 2018.0. and i have a following issue -

I realized that this version is very problematic - anyone can’t open 2018 file in older (2017) muse version. it can lead to many questions and dissatisfaction from costumers because almost all have a 2017 version. What should i do? i’m already created a full home page in newer version and it’s impossible to convert it to 2017 version.

Besides, Envato upload page even don’t have the option to choose 2018.0 version.