How to get Astrill VPN to work on Flint 2 while in China

Hi all, I purchased the Flint 2 specifically for the purpose of having a whole route VPN while I'm on in China for two years on work assignment. I read that Astrill has been the most reliable router VPN to use here but can't get pass the "connecting" yellow light. There was a post about the same thing a year ago but it was archived without any comments. I'd really welcome any advice! Thanks in advance :-)