If you're using a different version of POIYOMI manually change the shader to poi where it says (shader error/hidden).

Your blueprint is still detached and needs to be unattached. Reference this video for how to remove!

If you see red errors saying something is missing, it's likely due to improper importing of dependencies such as SDK3, Poi, Dynamic Bones, or DPS. This can also happen if you're using outdated versions. To avoid this, make sure to use the latest versions and update your packages regularly. MAKE SURE ALL IS UP TO DATE!!!! Meaning fresh unity package, NEWEST SDK, your version of Poi, DPS most updated package. Common errors can happen if you are using OLD versions of them.

The main reason for errors might be an outdated version of SDK3. To solve this issue, download the newest version of SDK3 and delete the old SDK3 folder in Unity. Save and close the project, then reopen it and drag in the newest SDK3 download. Another reason why you may not be able to upload your model is if your computer's storage space is insufficient. Ensure that you have enough storage available for uploading, as otherwise, the model will not be able to upload.