Gmail is still working with 3.5.23

FF 53.0.2 64 bits

Recently Gmail updated their login page, and by default, the account is activated in high-security
so disable in low and wait a fews hours !

For 4.0.2 (never working for me)... try my method too!

add:  fews hours = 20h

work with 2 gmail + 1 yahoo + 2 hotmail >

I confirm your contribution.
After updating X-notifier to version 4.0.3 Gmail stopped working, although hotmail was still working, in Firefox 54.
I searched for version 3.5.24 of X-notify and Gmail ran again without problems, although this version does not support the multiprocess of Firefox.