As for the announcement from google and JFlog, JCenter is closed(read only).
All active maintained libraries are moving to other repository like maven central or Google.
But your released zoom-sdk-android-188.8.131.527 mobilertc depends on JCenter.
The exoplayer and flexbox already have moved to google repository.
Could you update the dependency on build.gradle?
These are latest dependencies for exoplayer and flexbox.