I'm having a similar problem, but it looks like all of my images failed.
2018-11-26T11:18:58.468: Loading raster datasets
2018-11-26T11:18:58.564: Completed crawling 124 data source items. Added 124 mosaic dataset items.
2018-11-26T11:18:58.578: Synchronizing crawled data source items
2018-11-26T11:18:58.605: Synchronizing items associated with raster type instance 'UAV/UAS' [ID: 1].
2018-11-26T11:18:58.616: Distributing mosaic dataset operation across 2 parallel instances on the specified host: [NRES-BLCC582].
2018-11-26T11:19:08.284: Error: 8004206c: Failures reported while processing specified command item. [101]
2018-11-26T11:19:08.287: Error: 80042019: Chained Error ID: 0X80042019
2018-11-26T11:19:08.297: Error: 80042019: Could not build mosaic dataset item. [ID: 101, URI: 'C:\Users\krohling\Pictures\Drone Images\Images\11_8_2018\LOMA 1\DJI_0101.JPG']
2018-11-26T11:19:08.304: Error: 80004005: Creation of frame camera model failed.
2018-11-26T11:19:08.313: Error: 80004005: The altitude is too low at: -40.066156 meter.
2018-11-26T11:19:08.322: Error: 8004206c: Failures reported while processing specified command item. [102]
2018-11-26T11:19:08.329: Error: 80042019: Chained Error ID: 0X80042019
2018-11-26T11:19:08.337: Error: 80042019: Could not build mosaic dataset item. [ID: 102, URI: 'C:\Users\krohling\Pictures\Drone Images\Images\11_8_2018\LOMA 1\DJI_0102.JPG']
2018-11-26T11:19:08.343: Error: 80004005: Creation of frame camera model failed.
2018-11-26T11:19:08.354: Error: 80004005: The altitude is too low at: -40.602738 meter.
And so on...
2018-11-26T11:19:20.921: Error: 80004005: Creation of frame camera model failed.
2018-11-26T11:19:20.923: Error: 80004005: The altitude is too low at: -39.371364 meter.
2018-11-26T11:19:20.941: Error: 8004205e: 124 mosaic dataset items could not be built.
2018-11-26T11:19:20.994: Removing invalid mosaic dataset items
2018-11-26T11:19:21.116: Removing unreferenced raster type and overview instances
2018-11-26T11:19:21.134: Removed 124 mosaic dataset items and 1 unreferenced raster type instances.
2018-11-26T11:19:21.389: Removing broken mosaic dataset items.
2018-11-26T11:19:21.459: Removed 0 mosaic dataset items and 0 unreferenced raster type instances.
2018-11-26T11:19:21.646: Completed synchronization: 124 items selected, 0 items synchronized.
ERROR 999999: Something unexpected caused the tool to fail. Please refer to the error help for potential solutions, or contact Esri Technical Support http://esriurl.com/support.
Failed to execute (AddRastersToMosaicDataset).
Failed at Monday, November 26, 2018 11:19:23 AM (Elapsed Time: 32.92 seconds)