loading spritesheets in monogame extended

Can anyone help me with an exception that extended throws?
i told it to:

SpriteSheet spriteSheet = Content.Load<SpriteSheet>("Rat.sf", new JsonContentLoader());

and it told me

Microsoft.Xna.Framework.Content.ContentLoadException: 'Could not find ContentTypeReader Type. Please ensure the name of the Assembly that contains the Type matches the assembly in the full type name: MonoGame.Extended MonoGame.Extended.Animations.SpriteFactory.SpriteFactoryFileReader, MonoGame.Extended.Animations (MonoGame.Extended MonoGame.Extended.Animations.SpriteFactory.SpriteFactoryFileReader, MonoGame.Extended.Animations)'

I havn’t the faintest idea what this means and would like some help

I’m having the same issue - it looks like the SpriteFactory stuff looks abandoned? That’s my guess as there is no 3.8 release of the MonoGame.Extended.Animations which what the pipeline is referring to. There is only a 3.7 release (which I cannot use as it’s .NET framework only instead of .NET Standard)

I’m still looking for a solution, I’ll update if I find one.

Interestingly changing to this format worked for me:

SpriteSheet spriteSheet = new JsonContentLoader().Load(content, spriteAssetName);

Also note that it gets an error if the base image has the same name as the .sf file.
If your sprite sheet “Rat.sf” references an image “Rat.png” that will fail, but changing it to “Rat_01.png” or something will work.

Well at least it did for me.

OK I think I’ve worked it out.

The MonoGame.Extended.Animations appears to be no longer needed - and the documentation and examples are probably just out of date.

Content.Load(“Rat.sf”, new JsonContentLoader());
Will work as long as there’s no assets in the pipeline named “Rat”, due to the naming conflict that will occur when it’s converted to “rat.xnb” by the pipeline (as otherwise it will try load itself as the texture, that was overwritten. So “rat.png” became “rat.xnb” but got overwritten by the “rat.sf” becoming “rat.xmb”! and that’s the error)