Blender says manifold, S3d says not

[Hertfordkc]

Blender says this file is manifold, but S3D says it isn't. Can someone verify which is correct and advise a course of action?
https://www.dropbox.com/s/f2lr5ztktsizpkb/Ttbl.stl?dl=0
TIA

[dkightley]

I'm not in a position to advise if either Blender or S3D is advising correctly or not that there is or is not an error in the file.....but having run the file you supplied through the cloud repair service, S3D no longer says there are any manifold error.

I suggest you do the same: https://netfabb.azurewebsites.net/

[Hertfordkc]

Thanks for the tip. I'd tried to repair with another program, but it wasn't up to the job.