When sharing a mosaic dataset as a web tile layer or cached map image layer, the cache may not be generated properly if the number of rows and columns of the maximum image size of requests is set to a value less than 4096 by 4096. A higher value is recommended for improved cache generation.
Solution
Use the Set Mosaic Dataset Properties geoprocessing tool to change the number of Rows of Maximum Image Size of Requests and Columns of Maximum Image Size of Requests, under Image Properties, to a value greater than 4096 for an improved cache.
More information
See Manage a collection of imagery and raster datasets for more information.