If you have used, or have tried to use, Xchart with serial connections in the past you may have to reset permissions in Chrome. You can do that as follows:
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1. Clicking the little "lock" icon right next to the top.
2. Select "Reset permissions"
3. It's very important you refresh page after ward and try it again.
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If that still doesn't work, you can try closing Chrome altogether and trying it again.
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