The 1.7.10 pack crashing randomly

So I decided to create a server for the 1.7.10 pack to play with my friends. It is all fine and running smooth, but with some occasional lag. The problem is that after a while the server just crashes randomly. I can play for 10 minutes with my friend and then the server would crash. Please help.

We just started and we dont even have any machines. The max thing we can do is go mining rn.

Also after waiting in queue for half an hour to play on the new version of the pack, it crashed. I am really upset and pissed. I think this server should either be fixed or I should get a refund for all the time I wasted waiting. Thank you, and please help.