I had installed a virtual serial port driver on my Mac for an Arduino project around 6 months ago and it had been working fine, but a few days ago it stopped showing up as a serial port in the "Ports" tab in Arduino IDE for some reason. I have tried reinstalling the same driver but it still doesn't work, I've also tried this one (it was the only one I could find besides the first one) also without success.
If you know any other virtual serial drivers that have worked on your computer please write, I'm a noob here and I'd appreciate it a lot
You cannot use any driver, you need one that matches your hardware. What hardware did you connect to your Mac to should show up as a virtual serial port?
I was connecting the USB port directly to an Arduino Uno. I was using the CH341's driver and it was somehow working perfectly until suddenly the COM port that it had created disappeared
That Arduino UNO uses an ATmega16U2 as USB2serial converter and not a CH341. That may be used if you use a cheap Chinese board that may be named UNO but in that case it's definitely not compatible with the UNO. You need an AVM driver but I have no clue how the Windows driver is named (as I don't use that OS).