Mark, As you suggested I set the working machine (Win 11 main computer) to sync using mSecure cloud. The sync starts and after about one minute I get this error. Tried it multiple times, same error each time.

Update resolved issue, thank you!
So far so good. Updated iphone to IOS 26.5.2 and upgraded MSecure to 7.01(1112) and then re-enabled syncing to DropBox. Appears to be working correctly at this time and I will continue to test other features. Thanks Support/Development for addressing the issue.
Arafon1960
mSecure v7 on ios 26.5 iPhone 15 crashes on logging in
It firstly attempts to sync bbut after 2 seconds crashes out and screen reverts to ios menu
5 people have this problem