Sketch 49 issues
After updating to Sketch v49, this plugin will no longer apply a mask. It doesn't allow me to choose a color symbol as the mask color from the same document or any library even though the libraries are listed in the dropdown. 

After the import has finished some of the icons are not sized properly – they remain enormous in size.

[Screenshot](https://cloudup.com/cIWR8-0FUdj)