I can't scroll around the map in Firefox 64.0 64-bit

I can't scroll around the map in Firefox 64.0 64-bit A detailed description of the issue:&nbsp;&nbsp; I join my game as DM.&nbsp; The page loads. I scroll around to find my players' tokens. I can scroll for a few seconds, then the scrolling stops. Whatever was on the VTT at that time stays there as I continue to scroll.&nbsp;&nbsp; As I continue to scroll around, I get a little movement (about an inch) at the very end of the stroke, vertically and horizontally.&nbsp;&nbsp; My macros still work. The zoom bar still works, but zooming gives inconsistent results.&nbsp;&nbsp; If I switch to a new map, the whole VTT just goes gray. Sometimes I see part of the previous map tab.&nbsp;&nbsp; The game works fine on Chrome.&nbsp; Launching another game, for example, Underworld Speculation, that works fine in Firefox.&nbsp; Web Browser: Firefox&nbsp; Browser Version: 64.0 64-bit Operating System: Ubuntu 18.04 If Javascript is enabled: Yes Your anti-virus software: none List of any browser add-ons or extensions enabled: none&nbsp; Cookies enabled, Flash not installed, 1920x1080 screen resolution, 24 bit color depth Looking at the console output, when the scrolling freezes, this error shows up:&nbsp;&nbsp; IndexSizeError: Index or size is negative or greater than the allowed amount app.js:111 e.Lamp.prototype.castlight <a href="https://app.roll20.net/assets/app.js:111:3013" rel="nofollow">https://app.roll20.net/assets/app.js:111:3013</a> E/&lt; <a href="https://app.roll20.net/assets/app.js:344:2912" rel="nofollow">https://app.roll20.net/assets/app.js:344:2912</a> forEach self-hosted:262:13 k.forEach <a href="https://app.roll20.net/assets/base.js:6:1626" rel="nofollow">https://app.roll20.net/assets/base.js:6:1626</a> E <a href="https://app.roll20.net/assets/app.js:344:1" rel="nofollow">https://app.roll20.net/assets/app.js:344:1</a> P <a href="https://app.roll20.net/assets/app.js:344:6835" rel="nofollow">https://app.roll20.net/assets/app.js:344:6835</a> R <a href="https://app.roll20.net/assets/app.js:344:5950" rel="nofollow">https://app.roll20.net/assets/app.js:344:5950</a> d20.canvas_overlay.postProcessing <a href="https://app.roll20.net/assets/app.js:344:6048" rel="nofollow">https://app.roll20.net/assets/app.js:344:6048</a> d20.engine.postProcessing <a href="https://app.roll20.net/assets/app.js:344:31485" rel="nofollow">https://app.roll20.net/assets/app.js:344:31485</a> renderAll <a href="https://app.roll20.net/assets/app.js:339:32724" rel="nofollow">https://app.roll20.net/assets/app.js:339:32724</a> renderAll self-hosted:973:17 d20.engine.renderLoop <a href="https://app.roll20.net/assets/app.js:346:14132" rel="nofollow">https://app.roll20.net/assets/app.js:346:14132</a>

It happened with the scroll bars and mouse wheel. I don't recall if I tried the pan tool or not. The game is Dan's Tomb. Thanks for getting back to me, but I can no longer reproduce the problem.&nbsp; I'll use Firefox for tonight's game and report if the problem returns.&nbsp;