If you are connected to nicehash and the following error is displayed:

DevFee: ZEC: Authorization failed
: {"id":2,"result":false,"error":[0,"Failed",null]}

Add to the config file as a line again "-allpools 1". Eventhough Claymore says there is no need for nicehash to put this line, actually it seems still needed.

ZecMiner64.exe -zpool equihash.eu.nicehash.com:3357 -zwal YourWallet -allpools 1