One of the reasons that you might not receive your reward is as the following:
You might have installed Lords Mobile atleast ONCE (even if it is 1 or 2 years ago) the system will recognize that it is your phone or you have tried to install the game before.
You might have tried similar offers on different games that involved the installment of Lords Mobile, thus, it is not giving you the reward on OSM now.
IP. Your ip is identical (someone else from your network has completed this offer)
Same Apple ID or PlayStore user trying to do the offers again, this might be one of the reasons that you aren't receiving the reward too, you perhaps tried it on an iPhone and now you're doing it with an Android or vice-versa.
Time limitation: This is usually not known but you have a specific time to finish your task, I personally never knew how much time you get for finishing these.
Wrongfully clicked more than two LORDS MOBILE offers, if this happens the game will not reward you.
48 hour delay - some offers take up to 48 or 72 hours to give you the reward, if you do not receive it by now then something else is wrong.
If you're 100% sure that you none of the above happened to you then you must send an e-mail to the one that is providing the offer to you. You must provide proof to them that you have finished the offer but the coins are not being rewarded to you. You must also provide them with a special code that is assigned to your account depending on which platform you completed the offer, you find the support team e-mail and let them know everything.
I'm sure of one thing though, OSM has nothing to do with this as they're not responsible for rewarding you, they simply connect you with the offer and if the offer is completed right then you get the coins automatically.
@hespera Thanks the fourth method made the error go away.
So the DF-DFERH-01 error is gone now, but the problem somehow still occurs. I repeated all the steps of deleting the game reinstalling, force stopping, deleting cache and deleting data. I even restarted the phone but the game still closes as soon as the loading ends.
To be honest with you, I have no idea what you are trying to tell us. Could you please be more specific or post a picture of this message or something anyway? What platform are you using and where exactly did you find this message?