Ubuntu 14 runtime error

[cosminBucurest]

I get the following trace:
cc@cc-Lenovo-G50-80:~/SumoEasyMiner$ python sumominer.py
[21:20:02] [INFO] Starting [Sumo Easy Miner v0.1.b1.3]...
Starting app...
Traceback (most recent call last):
File "/home/cc/SumoEasyMiner/app/hub.py", line 141, in start_stop_mining
p.set_cpu_priority(cpu_priority_level)
File "/home/cc/SumoEasyMiner/miner/miner.py", line 594, in set_cpu_priority
_p.nice(cpu_priority_level)
TypeError: 'int' object is not callable