There is no and will never be no paid features.
In case you're familiar with Java, a security enthusiast, or just want to play around, there's the source code available for you.
There are popular Forge and Fabric versions in the launcher that can be installed automatically in just a few clicks. You can also install Forge and Fabric manually, just like with the official launcher.
It happens :) You can contact our free support (see below).
You can always contact us if something isn't working or not working as expected.
Our experienced developers and volunteers will try to help you.