call_user_func_array() expects parameter 1 to be a valid callback

There’s a mismatch between the filename and the setting that loads it. I worked around the problem by renaming inc/class-transient.php to class-transients.php and changing all of the occurrences of Debug_Object_Transient inside it to Debug_Object_Transients.

Thanks for the issue. I have fixed this small issue in the current development version. Maybe you can retest with this version and give me feedback?

Download: https://github.com/bueltge/Debug-Objects/archive/master.zip