[Eidolon not dropping arcanes]

Supposedly there is a bug introduced recently where the eidolon will be ragdolled if killed with a bow - including artemis bow - and subsequently not reward any loot.

[Possibly broken riven challenge]

I had a similar riven a while ago, which I also could not get unveiled in the plains. Dropships eligible to unveil such rivens spawn in corpus missions with open air areas.

[Riven challenge not completing]

According to the wiki, incursion refers to random missions appearing while on the plains. From the wording of your post I assume you might have mistaken it for something else.

[I can't move]

Have you changed your keybindings recently? If so, activating default settings / deleting the settings file might help.

[cant move]

Games will often save settings in a separate folder that will stick around if you delete and reinstall the game.

I found a file called "settings" in something like C:/User/Username/AppData/Local/Warframe/75453524342342, perhaps deleting this file will fix your issue.

[Zaw Finishers Unable To Proc "On Melee Channel Kill" Effects]

Wanting to build the zaw exodia "brave", I quickly looked it up on the wiki beforehand. Good thing I did, because I was told there that it is not working properly.

So the issue is, that zaw finishers do not proc effects which require you to kill an enemy while channeling (examples: exodia brave, mod dispatch overdrive). I quickly confirmed this ingame; Dispatch overdrive will activate from finisher attacks with a regular dagger - but not with a zaw.

I can only imagine the disappointment of a player spending a lot of time and resources on 10 essentially nonfunctional enchantments for their zaw, especially when the issue is easily replicated, identified and presumably fixed.

[No mods from Orokin Derelect]

Same issue. Frame of reference:

Orokin derelict survival / Mission completed after 20 minutes / Bleeding dragon key used, it was the last of the stack (after opening the vault I had none left in the inventory)

I opened the vault early and took the artifact later, about ~40 seconds before extracting. I did encounter corrupted enemies on my way to extraction and my shields were reduced from the artifact.

I noticed waypoints, which I had placed at the Vault, were disappearing quickly. They usually stay longer (indefinitely?) if I recall correctly.

Additional information: This was also my second solo run during which I had opened a vault, both using bleeding dragon keys. Nothing except the corrupted mod was missing. On the first and third attempt I got the mods as expected, however I waited until 5 minutes had passed before opening the vault and completed the mission immediately both times.