So that seems to point at the changes you have made. An immediate crash is often caused by an image that Android can't handle. Take a break and go through my Check List: https://www.professorcad.co.uk/appinventortips#TipsApk
The new version of the List View does not display lines - MIT are aware and hopefully we will see that fixed in a patch release.
Everything is affected by the upgrade because Google have introduced new (tough) security measures in Android 11.
App Inventor's own File Blocks can now save to the ASD. Much depends on what you are using Taifun's File Extension for, but you will have to contact the developers of all the extensions you use to find out if they are Android 11 compatible. If you start with Taifun's library of extensions, you may find out the compatibility via each link.
I can only say it for my extensions, and they also work after the update. The TaifunFile extension should also work, but since the targetSdk = 30 update (nb187...) it is no longer possible to save in external storage (outside of the ASD or shared storage), see also here.
Thank you very much for all your explanations. The other strange behavior that I've noticed is the fact that the application crashed as soon as I try to search for value in the List View.
I can confirm that the List View has a problem with the search feature.
I've rebuilt the old version of the application that was working fine when compiled in August, and now it crashed every time I try do search the List View.
Hello!
I have create one application in june & the application was working fine but yesterday i have made some changes on Application so now List view Search option is not working When we try to type any thing in Search option so application were crash, Do any one have the solution for it please help me in it.
There isn't a work-around unless you want to build your own ListView (HTML Table) or use an extension. MIT are working on the ListView bugs and so hopefully we will see a new update soon.