The 'sort' icon is not available in the KPI grid in order to sort the data. What could be the reason?

The 'sort' icon is not available in the KPI grid in order to sort the data. What could be the reason?

The images must be missing from the IMAGES folder as part of the Application configuration. Ensure the required images is available in the 'IMAGES' folder as part of the configuration. Please contact ARC Support team for further assistance