actually nvm this one's my fault, this is being caused by some code related to indents
It's effecting empty strings, since the code is trying to get the indent of the first character in a string, which doesn't exist.
Replace line 1907 with this:
Vector3 pos = new Vector3(info.Count > 0 ? info[0].indent : 0f, 0f, 0f); //keep track of where to place this text
and line 1921 with this:
float lineWidth = info.Count > 0 ? info[0].indent : 0f;
I'll publish a hotfix right now!