I've noticed a strange behavior pop-up 3 or 4 times within the past few weeks (Sep-Oct 2016): after running aMule for a while (sometimes minutes, sometimes hours), right-clicking on the downloads "All" category tab suddenly has no effect, i.e. the categories contextual menu does not appear any longer. As a result I cannot switch from filtered downloads (active downloads in this case) to all downloads, resulting in an inability to start downloads that are in a stopped or paused state.
The obvious workaround is to exit aMule and restart it, which works fine, but that implies stopping current downloads and possibly re-entering a peer's wait-queue at the end which, when sources are rare and in high demand can be a real pain in the backside.
Another graceful possibility would be to activate (pop-down) that contextual menu with some keyboard shortcut (the equivalent of a mouse right-click) when focus is on the "All" category tab. Unfortunately I've found no help thus far on the web indicating which key or key-combination emulates a right-click, if at all. I've tried the obvious Return, Esc, down-arrow with and without Shift/Ctrl/alt... without success.
Would anyone know if a) such a keyboard shortcut exists and, if so, b) which is it?