It just seems to me that RM8 just does not support an Android App. I had no problem with the Android v1.4 app on a Pixel phone with RM7. But when I switched to RM8 and tried to open it in the Android app crashed. I did all the following:
I followed all the steps in the FAQ “Android App Crashing or Forced Closed” with the v7 file. No help.
I then followed the instructions to export the v8 file to v7 format and again ran the database tools with no errors reported, uninstalled and reinstalled the app, three times. After each try, the app opened, but when I selected the rmgc file in Dropbox I received an error message and the file would not open, but the app did not crash. I actually have two different files and the results were the same with both.
I then went to an older PC laptop that still has version 7 installed and opened the file in Dropbox with no problem. I again ran the database tools in v7 and there were some indexing errors found in the integrity test, which were fixed by Rebuild Indexes. I ran all the tools again and they reported no more errors.
I then again reinstalled the app and tried to open it and once again it will not open. Just continually crashes and closes until Android reports that the app keeps stopping.
In v7, I tried to save a backup of the exported v8 file (now v7 again) to Dropbox and received a message from Dropbox that my current browser (v7?) is not supported. It did however save another copy of the rmgc file in a TempRMBackup folder under Apps\RootsMagic.
On April 27, 2022 I reported all of this to RM in an email and received the following response:
"Thank you for contacting RootsMagic Support.
I will do the testing the best I can, I just don’t currently have an Android device to work with.
I have not heard anything since. Apparently no one at RM uses Android phones. Also, the RM8 Wiki only mentions using the iOS app, not Android. RM7 previously specifically supported the Android app, however the Wiki cited by rzamore1 re using RM7 did not work for me.
Conclusion: give up trying to use the RM Android app with RM8 (or even 7 now) and use TomH’s suggestions.