Minify generating error in log

I have just been looking at our error log and found a few instances with Hummingbird minify, could someone please take a look and advise if we can fix these errors?

[27-Mar-2017 05:46:01 UTC] PHP Notice: Undefined offset: 0 in /public/wp-content/plugins/wp-hummingbird/core/modules/minify/class-minify-group.php on line 1078

[27-Mar-2017 05:46:01 UTC] PHP Notice: Undefined index: in /public/wp-content/plugins/wp-hummingbird/core/modules/minify/class-minify-group.php on line 554