If you are using an older or rare browser, you may run this error in Post Planner:
Browser not supported
The Fix
You will need to switch to a browser supported by Post Planner.
Post Planner supports the following browser versions:
Chrome 83+
Firefox 78+
Safari 12.1+
Opera 68+
Edge 83+
If user is getting the error popup, check if their browser is supported first. It may work with older versions but it is not 100% guaranteed.