I am having trouble updating a product with the firmware update file using NRFconnect app for ios version 2.5.3 using iphone se 2020.
We have been running successful updates for 7 years on the nRF51822.
I have used NRF apps in the past to update products. Several days ago our product was failing to update using our custom app. When this happened I decided to try with the NRFconnect app and I got this error (see attached image).

Please let me know what causes the error.
What other information do you need to diagnose this problem?
Thanks
