When I finished the first set in the mission chain that was composed of previously released weekly missions, I clicked the "next mission" button. However, since I did not have sufficient energy to begin the next mission in the chain, I exited out. Unfortunately, as soon as I exited out of that mission chain, it disappeared from my list of available missions and has not returned. Now it looks like I cannot complete any more of that mission chain. Does anyone know how I can get this mission chain back?

do you remember the name or details of the specific mission you just completed?

if you ran out of energy on the last of the previous mission and go to procceed to the next in the chain and find that you do ont have the energy it reverts back to the mission that you just completed. go into that mission and it will say proceed to next mission. It happens to me alot. And if thats not the case I am sorry but i have no idea

There is a chance that it is on your mission list, just in a different spot then the one you finished was. If it had a level requiment on a later mission it will most to the point on the list that it should be.

This happens a lot, just keep your eyes open.

if you remember the details or the title of the mission you finished, you can look for it in the wiki, and from there find the title and details of the next mission in the chain...

.....and then search your mission list for that one... or remember whether you've completed that one when it was a timed mission, if so, the one after it is the one you're looking for.....