Spine - File is not in container

So, I'm trying to figure out whether Spine import feature is working (before I buy any licenses). I was playing with import of standard Spine examples from their webpage ("alien",  "coin", "dragon", "owl"). Using some tips from this forum as well.

Got some progress on this front and some partial success, but there are also some evident issues.

First, one needs to rename the .atlas file to match the name of imported .json.

Second, the "images" folder needs to be placed as a subdirectory of folder containing the imported .json.

This usually allows to import some of images and animations from the file.

There seems to be another issue with animation names, and how they appear in the outfit menu (but that's minor for now).

However not all animations are imported (or at least not correctly). Looking at the editor log (viseditor.log), it's still failing with some paths.

There are multiple entries "File  is not in container" but no missing file path is given.

Since there are 2 spaces between "File" and "is" looks like either path is not logged properly or filename constructed is empty/messed-up.

Any tips to solve this?

Is there another way to look up what went wrong?

PS. Windows10 VS 5.1.4.2 build 1214

The error "is not in container" happens when there is no animation selection, even if it looks like one is selected you might need to reselect it, so the image is shown. Try that.