[secondlife error in upload request ?!!!]

Okay I installed the official viewer, and tried to upload three textures in a bulk.

I got the error for the first file after a relatiely short time. Then... the two others uploaded just fine. 

So I retried the first and it uploaded.

?! What now...

[secondlife error in upload request ?!!!]

The problem persists here.

I thought I'd give 5.0.1 a try... No luck.

I went back to 4.7.7 again, anything after that I can't upload textures.

Ah yes, I can upload a texture if it's a few pixels by a few pixels, that is one of the million crazy things I tried back then when I first had the issue with 4.7.9

 

What worries me is that now 4.7.7 is the oldest authorized version..... What happens the day that is blocked ?