Terminator won’t start

I ran into a stupid error.

My terminal client Terminator wouldn't start on ubuntu and I didn't get any no error either.

I started it via terminal. Here I got the following error:

/usr/bin/terminator
except (KeyError,ValueError), ex

I found the problem and solution
python3 was changed to my default system python

=> changed it back to 2.7, everything works again

I use update-alternatives

you can set up things easily. eg. python

check if it's maybe already set up for python

# CHECK if setup for python
update-alternatives --list python

otherwise set up the alternatives

# SETUP ALTERNATIVE 1
update-alternatives --install /usr/bin/python python /usr/bin/python2.7 1

# SETUP ALTERNATIVE 2
update-alternatives --install /usr/bin/python python /usr/bin/python3.6 2

and configure the version you want to be used by default

# CONFIGURE
update-alternatives --config python

There are 2 choices for the alternative python (providing /usr/bin/python).
Selection Path Priority Status
0 /usr/bin/python3.6 2 auto mode
1 /usr/bin/python2.7 1 manual mode
2 /usr/bin/python3.6 2 manual mode
Press to keep the current choice[*], or type selection number: