当项目里显示动图用到了FLAnimatedImageView，SDAnimatedImageView，YYAnimatedImageView就会有这个问题
14.0 系统调用了此方法，没有正确处理

- (void)displayLayer:(CALayer *)layer;

解决如下，找到这个方法

- (void)displayLayer:(CALayer *)layer {
    if (_curFrame) {
        layer.contents = (__bridge id)_curFrame.CGImage;
    } else {
        // If we have no animation frames, call super implementation. iOS 14+ UIImageView use this delegate method for rendering.
        if ([UIImageView instancesRespondToSelector:@selector(displayLayer:)]) {
            [super displayLayer:layer];
        }
    }
}

解决办法
升级最新版SDWebImage
或者
修改SDAnimatedImageView文件里的displayLayer方法
增加判断
if ([UIImageView instancesRespondToSelector:@selector(displayLayer:)]) {
[super displayLayer:layer];
}