Compressing a file geodatabase while data, such as a table, feature class, mosaic dataset, or raster dataset, is being previewed or displayed results in unreadable data.
The following error may be displayed when previewing a feature class:
Error: "Open Failed Error opening feature class Access denied [feature class name] Access denied [feature class name] Access denied [feature class name]"
The preview or display of the data opens a lock and the lock prevents the compression from completing successfully. This occurs when running the Compress File Geodatabase geoprocessing tool in the background.
The problem can be avoided by not previewing the data just before compressing. Close all previews and refresh the catalog view prior to compressing the data. Remove the data if it has been added to an ArcMap session. If the above error is received when trying to access file geodatabase data: