Several people have not been able to upload Mesh in ADITI, the preview grid, but they can in AGNI, the main grid. Most often this is because they have not run through the Intellectual Property thing for ADITI. Yes, you have to do it twice, once for AGNI and once for ADITI. For ADITI visit: https://secondlife.aditi.lindenlab.com/
Also, after viewer and server updates some people are crashing when the attempt to tp to the mesh sandboxes. See: VWR-26698
Also, the 3.0.0 has a video gotcha that causes some people problems. If you are having a problem, visit the Snowstorm Page and get a copy of the latest development viewer. There are some video fixes included that have helped some users.
If you are having a tussle with mesh in ADITI, visit the Mesh Project to get an even newer version of the Mesh Development Viewer. Remember. This viewer is not always using the latest trunk code. It can be a mix of new and older code depending on what they are working on. So, there is risk in using it. But, you should at least have different problems…
Each of these viewers installs into its own folder. So, you can have them all installed at the same time. I do.
While I think it is a good idea for every viewer to use its own cache, giving each its own cache is not as important as it once was. Also, these viewers are very similar cache content-wise. So, if your just doing quick troubleshooting it should not be an issue, just keep clearing the cache.