Unity not recognizing new animation clips on overwritten Blender-exported .fbx

So I've got a .fbx with animations exported from Blender in Unity; in Blender I've made each animation as a separate Action, so in Unity each Action is recognized as a separate animation clip. So far, so good!

But when I've made some new animations in that file (in their respective separate Actions in Blender), and export it and overwrite the old one in Unity, Unity simply doesn't recognize the new animation clips. What do I do? How can I add the new animations without losing all references of the current file in Unity?

 

This is not Blender specific. Basically Unity fbx animations work like this:

• You can export and override fresh fbx as much as you want. Every time you do, the animations in the fbx inspector settings (importer settings) will be repopulated. Try it yourself with a fresh fbx.
  
• If you touch ANY setting of those animation entries in the inspector (set a "Loop Time" flag, add animation events, root motion, any change, animation timing), or you rename / add / delete any entry, Unity will save those changes in the meta file of the fbx file. Unity does this as it is not allowed to modify the original fbx. Once this happens, Unity will stop repopulating overridden fbxs as it wouldn't know what to do if you rename / add / remove / change timings of any take in the fbx itself.
• From that point forward you have to add / remove / rename your clips manually. You can do that by pressing the "+" or "-" sign at the bottom of the list (check the screenshot). Once you added a new animation entry, you have to specify which take (from the fbx) should it use as a source.
• From that point forward (again) - ALWAYS CHECK FOR TIMING CHANGES AND SET THEM MANUALLY. I.e. if any of the old takes changed its start or end frame (basically duration). They won't be automatically updated by Unity. (check the screen shot again).

I agree, this totally sucks! And the Inspector interface is a pain in the ass to work with. We've created a tool to help us with that but it is not ideal. And the workflow is horrible if you have many animations in single fbx.

 

This helped me a great deal, thank you NibbleByteSSG.