Stuck on "Receiving Data" for Mac

I have been playing Rust on my PC for weeks without an issue and just bought it on a mac at home for my brother. When trying to launch on any server the game stops loading at receiving data and never passes this point. I cannot find any fix for this anywhere. Does anyone know what to do?

Probably is the 3d render laptop have very low fps in 3d rendering and cpu usage!

what type is your Mac and system info?

iMac
Yosemite 10.10.4
Processor: 2.8 GHz Intel Core 2 Duo
Memory: 4 GB 800 MHz DDR2 SDRAM
Graphics: NVIDIA GeForce 8800 GS 512 MB

Mac OS X

MINIMUM:
OS: OS X Lion 10.7
Processor: 2 ghz
Memory: 8 GB RAM
Storage: 2 GB available space
RECOMMENDED:
OS: OS X Mavericks
Processor: 3 ghz
Memory: 8 GB RAM

RECOMMENDED:
OS: OS X Mavericks
Processor: 3 ghz
Memory: 8 GB RAM

U might be a little under specs. looks to me that could be processor to low and graphics card is low below under the MINIMUM Just a comparison to Mac, what windows are you using ?