When I run strategy tester,on my local agent, the agent cpu usage showed on "agents" tab increate quickly and the test is down with cpu usage
up to 100% and status change to busy. even i run easy strategy like example moving average EA,like this:
it went wrong agent status after cpu usage grew to 100% usage,
busy because of promotion even or you need to upgrade core2 quad LOL.
i found this on first load not in progress actually it just take 1 - 4% CPU on single core older intel processor. so you need update your MT5.
also try to increase your virtual memory.