I made a mouse-driven PICO-8 game for Ludum Dare 40 which requires you to click and drag the mouse. In PICO-8 I never had an issue but in the HTML export it sometimes fails and the cursor becomes the 'cannot drop' icon, a black circle with a diagonal like this http://www.expd8.com/UserManualV4/CaseActivities2_files/image016.jpg

I'm guessing I need to edit the generated javascript in some way but know nothing about webdev, I'd REALLY appreciate help as my game seems popular but lots of people are hitting this inconsistent issue :(

You can try it yourself here https://rhythmlynx.itch.io/complicity-inc

I stumbled on that kind of problem, mostly fixed by adding to the canvas css like this:

canvas{
    image-rendering: optimizeSpeed;
    image-rendering: -moz-crisp-edges;
    image-rendering: -webkit-optimize-contrast;
    image-rendering: optimize-contrast;
    image-rendering: pixelated;
    -ms-interpolation-mode: nearest-neighbor;
    border: 0px;

    cursor:none;
    -webkit-user-select: none; /* Chrome, Opera, Safari */
    -moz-user-select: none; /* Firefox 2+ */
    -ms-user-select: none; /* IE 10+ */
    user-select: none; /* Standard syntax */
    user-drag: none;
    -webkit-user-drag: none;
}

hope that helps (I'm no fluent in html5)

@ultrabrite that seems to have fixed it, THANK YOU!!