Thank you for your report and for all the detailed log message and stack trace information you have provided; very helpful.
I believe you are encountering the same issue reported in this recent topic:
I can’t uploads files – v2.12
I have made some updates to the MLA Development Version to correct that problem. It would be great if you can try the latest Development Version and let me know if it works for you. If that is not possible you can avoid the problem by disabling the “Bulk Edit on Upload” feature as described in the earlier topic.
If the Development Version does not fix the problem I can work with you to activate more detailed debug logging and investigate further. If you send me your contact information and I will respond with an email address where you can send login credentials, error log content and any other information you think helpful. You can use the Contact Us page at the FTJ web site:
Fair Trade Judaica/Contact Us
Do not post your e-mail address in the forum; personal details in a public forum violates WordPress guidelines. If you have trouble accessing the FTJ site, post a note here with your country of origin and I can temporarily unblock it.
Thank you for your help and your patience in awaiting my response.