1 wall is empty for me, others load some tasks. are you trying from PC or Android/iOS?
same here
I don't have any problems with my "Contracts" Tab ... weird ...
same for me
Yes, Pc and Android
I dont know but many people expirienced bugs thatt they dont get their gems by doing the contracts idk why i had the same bug too :/
I don't think this is a bug, i think it is a recent change by Gamehag, removing certain advertising or filtering advertisers on your location.
This mostly because some advertisers just never pay to some people (mostly because your location)
Example:
I live in Indonesia
One 'Wall of- ' ' was from advertiser Fyber
I did a few contracts from Fyber, NONE of them gave me my earned rewards
I battled with Fyber support, in the end they gave me the finger on each and every case
I reported my issues with them to GameHag (just like many others like me i assume)
Soon after i reported this to GameHag, all the Fyber offers (1 'Wall of- ' ) disappeared from GameHag
Later i heard some users still doing Fyber contracts on GameHag, but non of them from Indonesia
I think GameHag got tired of being flooded with support questions while there is nothing they can do about this
Actually this is a good thing, you do not need a 'Wall of False Promises' that just waste your time and never pay
I just gave up 
i got over 4000 sgs from fyber offer. Too bad if they removed it
in 3 steps
Choose the game that interests you and play itfor free.
Every game has some quests for which you will receive Soul Gems.
You can exchange your Soul Gems for Steam Wallet top-ups, game keys, CS:GO Skins and other rewards.
You know that on Gamehag you can get real rewards for free, right? Join us, complete walkthrough and get your chest!
is something wrong with contracts? some bug? I mean... I cannot open the tabs (wall of something) only nightmare..