Hello,
since Firefox Quantum
(version 57), the addon Jsonview
to display JSON beautifully is obsolete.
Json contents are displayed as raw text, in black and white.
Test it with this BMA url :
https://g1-test.cgeek.fr/blockchain/current
But you don’t need an addon anymore…
Type about:config
in the address bar, then search this jsonview parameter :
devtools.jsonview.enabled
Set it to “true” and taa taa !
Test it again with this BMA url :
https://g1-test.cgeek.fr/blockchain/current
Enjoy.