Mesh objects have a max face limit of 8, if you are uploading mesh that exceeds the vert count (64,000) or tri count ...then any remaining faces you might have under or over 8 will be split into a 2nd mesh automatically on upload,(firestorm) it's not a upload issue it's done to aid you in getting your mesh in with out breaking the system, what this boils down to is it's a poor creator not checking what the upload limits are and ensuring your tri and vert counts don't exceed the upload limit.

You can upload a single mesh item with 1 face with a vert + tri count in the 150k area, but the uploader will split it into a 2nd mesh to cope with your mistake!

If your having texture issues and your textures ar'nt connecting to the face correctly & or the textures are a random colour when applied all over,

this would indicate that you have not set your UVMap correctly for the object.

Basically you have one or more INACTIVE UVmaps still attached to the object, this usualy occurs when you poach mesh from 3rd party sites as their mapping is sometimes named diffrently, joining parts together to form a larger single piece will result in most cases of the active uvmap displaying correctly in blender, but when exported and uploaded to SL, the system dose not know which uvmap it should be uploading so it picks one at random. (see attached image)

1000's of creators do not have this issue, ( i deffo don't and i upload hard surface hi-poly models as standard) which means the issue lays with the creator not the system.

So what your saying is your mesh exceeds the limits set for the uploader ? https://wiki.secondlife.com/wiki/Mesh/Technical_Overview

Hi GetMeshed

When filing a Canny please provide more details of your problem. Without this information your Canny will be closed as Needs More information and will not be triaged.

Please include:

Thanks!