This is really long so I apologize beforehand...

Been trying to import a mesh to a hair package file but got the index out of range error

Was following this video tutorial

Got the mesh by extracting a S4 hair to convert it to S3. It's a really long hair that reaches the lower back

Went looking for a similar hair with the same length to make the process easier but couldn't find one. Got one that was similar but not the same length (don't know if that changes anything) and it had two groups (group_0 and group_1)

Extracted the mesh from the .package of the CC that I'm using as a base. Put it on Milkshape to get the group_base. Did the same with the mesh I want to convert

Put them both on Mesh Toolkit. No problem there.

Put the resulting file back to Milkshape, changed the name to group_1, with an empty group_0 that I got by getting the .wso of the base CC

Then I got the message:

"Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: Index"

Then the program closes

Already tried to do the whole process with different CC hairs as a base. Rechecked the group's name and the order but keep getting the same error

Anyone can help? I'm certain I'm losing my mind

This error happens sometimes when trying to import a high poly mesh in the mesh tab. Try instead clicking Edit>Project Contents in the upper left in TSRW, then right click the GEOM you are wanting to replace, click "import" and import your .wso that way. For this, you'll need to separate Group 0 and Group 1 into 2 different .wso. You can tell which LOD you are importing over based on file size and they generally go in order. So if you are replacing Group 0 and Group 1 of the Very High LOD, you would replace the first two GEOMs in the list respectively.

You might need to go to a different group in the mesh tab then back to the one you imported over to get TSRW to show your imported mesh after this.

What do you mean by "empty"? There must be a mesh. I use a single tris, that I place in the center of the head, and paint HeadNew, so it doesn't pop out anywhere.

It was indeed because of a high poly mesh... finally figured out how to lower the polycount in blender 🫠

Got tired of the two groups issues so instead I managed to find a hair with only one group

So the problem got solved, and I learned something new lol