My apps were working fine and suddenly started crashing on older devices. I have iPhone 7 Plus to test and after updating it to 15.7.8, the installed apps which were working before started crashing. The specific code where they are crashing is
if([testStats objectForKey:TEST_STATS_ARRAY]) {
statArray = [testStats objectForKey:TEST_STATS_ARRAY];
}
else {
statArray = [[NSMutableArray alloc] init];
[testStats setValue:statArray forKey:TEST_STATS_ARRAY];
}