On apps with compileSdkVersion above 31, this error will be thrown when trying to send an SMS:
Targeting S+ (version 31 and above) requires that one of FLAG_IMMUTABLE or FLAG_MUTABLE be specified when creating a PendingIntent. Strongly consider using FLAG_IMMUTABLE, only use FLAG_MUTABLE if some functionality depends on the PendingIntent being mutable, e.g. if it needs to be used with inline replies or bubbles.
On apps with compileSdkVersion above 31, this error will be thrown when trying to send an SMS: