Hi, I have a late 2013 iMac (24 GB RAM and 4GB graphics) and until I installed the latest Mojave update, everything was running fine. After installing the update, my system's become erratic, "laggy" and the mouse pointer freezes then jumps every few seconds! I can't get any work done and just switching from one application to another has become nightmare. Has anybody else experienced this? Is there any way to fix it? Is it a hardware (or keyboard/mouse) problem or has Mojave just destroyed my iMac??