I had code that compiled and ran on UNO, then needed to migrate it to ESP32. Set up usual board (DevKit) and port (com4 in my case).  VERIFY and got immediate error “& was not expected here”  
What?? Pulled stuff out of the code until nothing but usual ‘new’ setup and loop. same error.  Did an actual “new” file, compiled with default filename and it compiled OK.
What It Was:  I had a very long filename for the .ino !  Saving same code to short filename it compiled, uploaded and ran fine…  
Just In Case someone else hits this weird error!
Regards, Terry King    …In The Woods In Vermont
The one who dies with the most Parts LOSES!    WHAT DO YOU NEED??