Index was out of range

I am going to train the field on how to use our first app today, and as I am testing from my phone before the training, I have a message on one that I tried to send that says :unable to add/edit/delete row in table ‘XXXXX Trouble Equipment Tracker; - Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index.

Hi @AprilB,
Please see my response via email.