Error: Problem parsing d="MZ" d3.v3.min.js:1

[vbauer]

Each time after dashboard is refreshed, I've got an error in browser console:

Error: Problem parsing d="MZ" d3.v3.min.js:1
a d3.v3.min.js:1
(anonymous function) d3.v3.min.js:3
Tn d3.v3.min.js:1
Ma.each d3.v3.min.js:3
Ma.attr d3.v3.min.js:3
S nv.d3.min.js:4

Sometimes I see another error:

Uncaught TypeError: Cannot read property 'values' of undefined nv.d3.min.js:4
(anonymous function) nv.d3.min.js:4
u

Browser: Google Chrome, 32.0.1700.77