I find myself frequently reading old discussions, both on this forum as on others. Much knowledge has been accumulated here, even though sometimes it's hard to find. I note though, that often illustrations have gone missing. I presume this is inevitable when the pictures are stored on other servers than the forum itself. So be it.
However, I tried to outsmart this in a recent discussion
by storing mere illustrations externally where space is not yet limiting, but long-term storage is uncertain, and uploading the graphs essential for understanding the points made to the forum. This seemed to work well, only now, after about two days, the external images are still there, but the uploaded ones have gone...
What did I do wrong?