I believe I'm getting a similar compile error and could use help. Did anyone respond to you? The site looks like no one did.
Here is my error. I'm just running any of the default examples from Nextions Arduino library. I've edited the NexConfig.h file to use just Serial. I'm stumped on why this isn't working now.
Nextion\Nextion.cpp:3:1: error: 'Nextion' does not name a type
Nextion::Nextion(uint8_t rx, uint8_t tx)
Unfortunately I got no response yet.
Either I do something wrong or nobody else uses the library anymore...