Your data frame or group layer has layer masking enabled. Layer masking is not supported in basemap layers.
- Use the provided solution to turn off layer masking for the layer on which it is enabled.
- Alternatively, if you want to maintain layer masking, you can move the layer out of the basemap layer.
Layer masking uses graphic clipping to achieve the mask effect. This type of clipping can slow the drawing performance of a map. For more information on layer masking, see About masking.