The error message you're encountering indicates that there are multiple layers intended for the same skin and slot combination in your Photoshop file, which have the same name. This is not allowed in Spine, as each layer intended to be a separate attachment within a skin must have a unique name. The error message suggests renaming the layers to make them unique or using the [ignore] tag for layers you do not wish to export.
Given the context you've provided, it seems like the script is correctly identifying a naming conflict within your PSD file. Even though you've been using this format for all your skin files, this specific instance has caused an issue likely due to duplicate layer names within the same skin and slot. To resolve this, you should ensure that each layer intended for Spine has a unique name within its respective skin and slot. If the layers are indeed meant to be the same and should not be treated as separate attachments, consider merging them in Photoshop or using the [ignore] tag on the duplicate layers you do not need to export.
