This error message usually occurs when you are trying to combine two or more chart types that are not compatible with each other. For example, you cannot combine a column chart with a pie chart or a line chart with a scatter chart.

To resolve this issue, you need to make sure that you are selecting compatible chart types. In your case, since you are trying to create a basic column chart with the names of the counties and the number of accidents for 5 years for each county, you should select only the column chart type.

Here are the steps to create a basic column chart in Microsoft Excel:

1. Select the data range that you want to include in the chart.
2. Click on the "Insert" tab in the ribbon.
3. Click on the "Column" chart type in the "Charts" group.
4. Select the specific column chart subtype that you want to use.
5. The chart will be inserted into your worksheet.

If you are still experiencing issues, you may want to check if your data is formatted correctly. Make sure that your data is organized in columns or rows and that there are no blank cells or extra spaces. Also, ensure that the data is in a numerical format and not in text format.