no worries
I bypassed the problem by uploading new pictures and giving them the same name as the ones which were already in the folder.
I however encountered another problem which already took me 5 hours to try and solve.
The color of the footer is now blue-ish and should be changed to a color green (#198754).
I know it is in the sp-footer but I don't seem able to change it...
I tried via the spbuilder -- no luck
I tried via changing the css files directly -- no luck
Color remains blue and in fact should be green
Any ideas ??