If the issue persists and these tips do not help, please feel free to fill in this form to submit a support ticket for further assistance. If this reoccurs, I recommend trying a hard-refresh of your browser window as a first step (Ctrl+Shift+R on Windows or Cmd+Shift+R on Mac.) This will refresh and clear your cache for that page- so to avoid losing any work, please ensure that your network connection is strong and your document does not show 'Saving' when you try this. If that doesn't work, and the issue is still not occurring in an incognito window, it's likely that a browser extension is causing the issue- in which case you may need to disable the extension when working in Lucidchart. You can start by looking to see if the CTRL key is physically pressed. If you didn't know, if you press any of the CTRL keys and scroll upwards or downwards, the mouse's scroll will produce zooming. From your description, it sounds like there might have been browser-related performance issues in the original window you opened the document in. As it turns out, one of the most common causes that will trigger this kind of behavior is a stuck CTRL-key. Issues like this can be tricky to pin down to one specific cause, as there are a number of things that might influence this for each user (like browser issues, extensions, mouse/keyboard device settings, etc).

Hi Michael! Thanks for contributing to this thread.

Scroll wheel zooms instead of scrolling