Same problem - yesterday wanted to change strategy, but it simply wouldn't run. After a lot of struggle took fresh 602 copy - didn't help, it even became worse - GUI didn't show strategies from config file and was throwing error trying to update something.
This morning a tried a fresh run once more and strategies loaded successfully with a bunch of new parameters, but gunbot is not running anyway, empty logs screen.
I see in telegram group a lot of such complaint, that GUI is not working and that 7 version is being beta-tested.
How can such unstable product is even being sold, if new updates and testing just crashes previous versions? People are losing money because of that.