Which version of splunk are you using?
The error says display.visualizations.chartHeight must be a plain integer. Can you find your xml code and search for chartHeight and see if any value is set or not.
But check if you are seeing any warning messages next to your display.visualizations.chartHeight. I think it's bit old property, if it's not supporting on newer version, you might need to remove it and save.
Regards,
Prewin
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