Plugin stops live preview etc.

[eyolf]

A combination of things happen, occasionally:

• live preview stops working: italics remain Roman on screen
• the keyboard shortcuts defined in my vimrc file stop working
• every time I press enter, two lines are added

This error message shows up in the console when these things happen:

plugin:obsidian-smart-typography:787 Uncaught TypeError: Cannot read properties of undefined (reading 'ranges')
    at eval (plugin:obsidian-smart-typography:787:86)
    at ln (app.js:1:274454)
    at t.iterChanges (app.js:1:271676)
    at Array.eval (plugin:obsidian-smart-typography:755:32)
    at app.js:1:292139
    at Zn (app.js:1:292237)
    at e.update (app.js:1:293570)
    at e.dispatch (app.js:1:434438)
    at fs (app.js:1:431351)
    at e.onChange (app.js:1:432962)

so somewhere there is a connection to the Smart Typography plugin; whether it is the culprit or just standing somewhere along the way, I can't tell.
I've now disabled the plugin, and the problem has disappeared.