You have an empty group layer in your document, which can affect performance.
First, check the drawing performance of your map service in the Preview window.
- If you see the need to make changes, remove the empty group layer from your document.
Group layers are used to organize contents in your document. Two scenarios help illustrate the use of group layers:
- Organizing your information thematically (for example, to group all the hydrology layers or parcel layers together).
- Grouping layers by their scale, where each scale has a different view that contains only the information relevant for use at that scale. This technique is used for creating high-performance cached basemap services such as those found at ArcGIS Online.