avrdude: stk500_getparm(): (a) protocol error, expect=0x14, resp=0x11 ERROR

Hi!
I'm trying to upload a program on arduino uno with esp8266 and a bunch of sensors to send data on a website. I get to compile the program successfully but when I upload it, the ff error message appears:

avrdude: stk500_getparm(): (a) protocol error, expect=0x14, resp=0x11

avrdude: stk500_getparm(): (a) protocol error, expect=0x14, resp=0x10
avrdude: stk500_initialize(): (a) protocol error, expect=0x14, resp=0x44
avrdude: initialization failed, rc=-1
Double check connections and try again, or use -F to override
Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.
this check.

avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x10

I'm using arduino uno and my IDE is ver 1.6.5.

I'd appreciate some help. Thanks!