When i log in to the farmer log, an error like this occurs
what is the reason of this?
It is a known issue and shouldn’t effect farming. Dev is aware.
but rewards are not reflected
It looks like you are just about finishing plotting 100G. That is not a lot of space compared to the >124PiB currently pledged to the network. In fact, you can expect a reward around once every 10 days on average. Luck means it could be 1 day but it could equally be 20 days easily. You need to win a reward before you will see your balance reflected.
You will need to be patient or increase your farm size.