I had RO2 uninstalled and decided to install it immediately with the opt-in beta. It got to 99%, having downloaded the 9.8 gb, and then started flashing between Update Paused and 99%. Tried restarting steam, tried verifying cache (was verified successfully) and I tried toggling the Keep This Updated thing. I tried opting out, but that sent it to 0%, so... I'm trying to reinstall it.
Do you need to install regular RO2, and then beta? Doesn't seem like it since they're two separate installations.
I'm having this problem too now.