When an arrow-end is added to a path, the console will send error message.

[vrbvillor]

Error: Invalid value for attribute d="M0,0CNaN,NaN,NaN,NaN,NaN,NaN"q @ raphael.js:10v @ raphael.js:10y @ raphael.js:10D.attr @ raphael.js:11Raphael.el.draw @ raphael.extend.js:96show @ scene7.js:66(anonymous function) @ scene7.js:46z.doc.addEventListener.e @ raphael.js:10

If I don't use arrow-end it'll be nothing wrong.

[litt1e-p]

maybe your stroke-width is too small...

[hadasmaimon]

in my case, the arrow line was smaller than the arrow-end triangle, so I set the min size of the path to be 11 var subPathStr = guidePath.getSubpath(0, Math.max(11, thisLength));