Loading in new levels

On Questionable ethics I got a bit lost and did not realise I needed to put the blast shield plug out.

Anyway after trying to find out what I needed going back and fourth loading in the other area down the stairs I realised what I needed to do but the Machine with the buttons on it went transparent to fire the laser and the wall that gets a hole melted into it did not appear either but I could get through.

Also loading back and fourth between surface tension and QE I lost alot of my weapons they simply disappeared alltogether.

Mines and mine fields also cause a lot of lag

Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valve’s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.