Beta client MAC OS Not downloading

My girlfriend has a mac and unfortunately had to send it in for repairs. When it was returned to her she had to re-download league. After doing so she is unable to get the Beta client to download. After all files have been scanned it shows the launcher screen and prompts me to press launch. After doing so the launcher closes and nothing else happens. I have personally gone through and looked through dozens of threads attempting to figure this out and it looks like it is a common issue with mac computers since this new update. I also went through and double checked all of the possibilities in the troubleshooting connection forum that rioters are pointing out to people and none of those options resolved the issue at hand. All help is greatly appreciated and i really hope that riot can get this fixed soon because she is really upset.