all the challenges are beatable. There are circumstances that you can put yourself in so you cant complete them.
If challenges are that important to you, simple rule…
stick with the group, If one person decides to “scout” ahead, they will trigger the challenge before the rest of the team can get there to help.
Archive - Collect shards. How to: DONT WANDER. follow the story, if you explore away from where your suppose to and scavenge chests and shards in certain areas you wont have enough for some missions, that’s the problem with an open world mission. There are 2 possible places for the shard collecting mission to trigger, and I know there are more then enough shards for both missions. I Solo’d those missions when I went ahead of the group 
Algorithm - Not anymore… they nerfed the ■■■■ out of them in the last patch. uber easy to kill now
“The one with wolf” lol “The Void’s Edge” - Only spot I know of where you need to kill certain enemies is when your passing through the ice caves area. Never had a problem finding the enemies.
The Void’s Edge - Swarmers. 2 problems with this mission that a lot of people don’t realize.
- cant do it with melee. the swarmers self destruct, and if the self destruct, it doesn’t count as a kill. so only range can kill them unless you are like El Dragon and just mow them down with clothes line.
-note- Wolf doesn’t kill the swarmers… he by passes that section all together, the whole… BAD TOUCH BAD TOUCH!!! bit… 
- If you advance to far into the map when the mission begins, it cancels there spawn and you wont have that many to fight.
-Note- I like playing Benedict in Story, and that part I usually completely skip by flying over the gap. I usually run to the trigger area to check the mission first now, just in case…
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Some other info I know SOME of you don’t realize… I say this because I see people walk past some of this stuff all the time. (so some of you that are having problems finding enough of something… I bet you missed a few spots)
Shards = You get shards from…
The GIANT crystals that usually power something.
The smaller orange crystals that stick out of the ground.
The Orange Translucent rectangular boxes that explode when you shoot/hit them.
"pick ups"
Shoot the small orange crystals to get a few drops instead of just running over them.
Open Loot chests (you can open loot chests by shooting/damaging them, faster when needing to open a bunch quickly)
Chests obviously, but destructables that drop pickups also count as loot boxes.
Shard Boxes, Crates, and those round basket ball size plants on the Eldrid planet also count. (and lots of people miss those)