"..\sprite.cpp:101 Action 'xyz' not found." when starting a level

[Rusty-Box]

For a while now, playing levels keeps showing several error messages for certain Actions not found for some reason.

Error messages such as:

[WARNING] D:\a\supertux\supertux\src\sprite\sprite.cpp:101 Action 'small-walk-right' not found. [WARNING] D:\a\supertux\supertux\src\sprite\sprite.cpp:101 Action 'default' not found. [WARNING] D:\a\supertux\supertux\src\sprite\sprite.cpp:101 Action 'flip' not found.