Image focal module up to version 2.4.3 became incompatible with Magnolia 6.2.40.

Image focal module doesn't compile anymore with magnolia 6.2.40

Technical details:

Magnolia 6.2.40 introduced a new version of imaging module 3.5.10 which introduces a new abstract method toInputStream in class AbstractLoader.

 
Class FromDamAsset in magnolia-dam-focal-common is extending AbstractLoader class, and therefore it is required now to implement that new method to have the module compiling again.