It still doesn't work for me i get messages like:
An illegal reflective access operation has occurred
Illegal reflective access by net.minecraftforge.userdev.LaunchTesting
Please consider reporting this to the maintainers of net.minecraftforge.userdev.LaunchTesting
Use --illegal-access=warn to enable warnings of further illegal reflective access operations
All illegal access operations will be denied in a future release
is this a 1.15.2 thing