Using latest dev versions:

When a field is set as editable on a page and the same page also uses VBO, the VBO actions will result in an Ajax error code 200.
According to my research this cannot be caused by VBO and would indicate a problem with another module handling Ajax, which in this case is Editable fields. After removing the editable field/unsetting it from its editable format, there was no error.

It may have to do with an error that I found earier today regarding Editable fields:

Notice: Undefined index: module in editablefields_fallback_formatter() (line 201 of /home/myoffice/public_html/sites/all/modules/editablefields/editablefields.module).
Notice: Undefined index: module in FieldInfo->prepareInstanceDisplay() (line 610 of /home/myoffice/public_html/m