Delete all objects (in Configuration - Repository objects) does not work properly

"Delete all objects" function does not work properly.

Actions:
1) Select checkboxes to delete all objects - for ex. total objects to delete = 6342 (screenshot #1)
2) midPoint begins to process selected objects, but delete only about half of selected objects - deleted 3192 out of 6342 objects (screenshot #2)
3) It is necessary to repeat the procedure