moveItemsToTrash Api error SyntaxError: "undefined" is not valid JSON

[bartczar]

Doing some massive cleanup I try to move to trash all items from one folder.

Here is the log:

Source read complete
Found items: 17466
Items to process: 17466
Moving 17466 items to trash
Processing 500 items
Processing 500 items
Processing 500 items
Processing 500 items
Processing 500 items
moveItemsToTrash Api error SyntaxError: "undefined" is not valid JSON
SyntaxError: "undefined" is not valid JSON

Then I retry the same operation:
Source read complete
Found items: 15466
Items to process: 15466
Moving 15466 items to trash
Processing 500 items
Processing 500 items
Processing 500 items
Processing 500 items
Processing 500 items
moveItemsToTrash Api error SyntaxError: "undefined" is not valid JSON
SyntaxError: "undefined" is not valid JSON

So it seems that retrying helps and hopefully I will be able to delete it all after several retries.