me and my friend where playing on our server and when it crashed due to MCserverhost going offline/crashing (around the 3rd of may), and then our mods stopped working, we tried to re-add the mods and they still do not work on our server, they do work on our side on singleplayer worlds.
mods that stopped working: Amber, Liteminer, simplevc, Just enough items, AMCDB