IDE 1.8.8 won't upload to Nano

Yes, many people have experienced this. Last year, Arduino switched to using a new bootloader in their official Nanos. They updated the Nano board definition to be compatible with the new official Nanos by default. This means that the default Nano definition no longer works with old official Nanos and all Nano clones or derivatives.

The solution is to select Tools > Processor > ATmega328P (Old Bootloader).