I noticed a few years ago someone posted this, but I consistently have this error in just the last year. I've been using GATC since its release and prior to the last couple months had never gotten this error. Not sure if it is related to the .12 release or something else, since I didn't use the sim for some time in 2016 and first part of 2017. Since I've started using again in the last couple months, whenever I get past about 3 hours in Rush Hour I get the OutOfMemory error. Screenshots below. FWIW, I also installed on a second computer, also an I5, but with only 4 GB of RAM, and the crash happens at almost the exact same time - after 3 hours in, once I've got to about 100 ops/hr. I know that I used to not have this problem because in looking at the Rush Hour High Scores I have quite a few that lasted longer and had a higher aircraft volume than this current one below. Any ideas? Does the new version require more memory? Should I revert to an older version?