Listpicker elements not showed on first pick

MIT App Inventor Help
10

Here is an example of how to show breadcrumbs for a nested List Picker.
The base table is pre-loaded at Screen Initialize time, so I was able to load at before Selection time ...

back
back555×175 13.4 KB

blocks
blocks748×1905 131 KB

Capture
Capture374×407 28.4 KB

Capture2
Capture2368×213 15.7 KB
Docs.csv (3.5 KB) DocumenterV4.aia (5.7 KB)
global Docs
global Selection
global Viewed
last
last515×151 11.3 KB

Load_List_Picker
Load_List_Picker748×308 28.4 KB

pop_Viewed
pop_Viewed534×141 11.6 KB

when Screen1 BackPressed
when File1 GotText
when File1 GotText695×268 20.1 KB

when ListPicker1 AfterPicking
when ListPicker1 AfterPicking517×255 18.9 KB

push_viewed
back
back555×175 13.4 KB

All blocks:
blocks
blocks748×1905 131 KB

None of my screens will load once I open the builder
What I did in the project was not saved
How do I Create a Multi-Level Navigation System for an Agriculture App?