Hi hotline_oh,
I'm not exactly sure how, but it is definitely possible to accidentally remove modules from their inverters. This was not done in the inverter configuration window, but while changing the string layout. i.e. I was assigning different modules to the already configured strings to move them around the roof & give a nicer layout.
I am now left with an inverter configuration that has a number of strings listed as "String 2 (0 Modules)". On 1 inverter there are 4 MPPTs with 0 modules assigned.
It is really quite frustrating that I will have to go through the process of manually assigning the strings again.