I started getting this error every time I visited a twitter URL.
Something went wrong, but don’t fret — let’s give it another shot.
It was also happening to others online but my browser switch helped me realise it must have been a plugin / extension I was using.
I tracked it down to the awesome uMatrix extension.
I was allowing rules for the initial site , but twitter needed rules allowed for its secondary twimg.com domain too.
This wasn’t obvious until the page was hard-refreshed after it failed loading initially.
Once I had allowed these rules Twitter started behaving as expected.
Hope that helps someone struggling.