"Invalid behavior: :lt.objs.eval/inline-exceptions"

[badnotes]

When I press Ctrl + Enter on a simple python file that only print a message, LightTable print some error info.

system: window 7 LightTable version:0.8.4

all console log:

"Invalid behavior: :lt.objs.eval/inline-exceptions"

TypeError: Cannot read property 'parent' of null
    at lineNo (D:\tools\LightTable\core\node_modules\codemirror\codemirror.js:5202:13)
    at changeLine (D:\tools\LightTable\core\node_modules\codemirror\codemirror.js:2797:15)
    at addLineWidget (D:\tools\LightTable\core\node_modules\codemirror\codemirror.js:4340:5)
    at eval (D:\tools\LightTable\core\node_modules\codemirror\codemirror.js:3104:14)
    at eval [as addLineWidget] (D:\tools\LightTable\core\node_modules\codemirror\codemirror.js:1435:28)
    at a (file:///D:/tools/LightTable/core/node_modules/lighttable/bootstrap.js:23761:52)
    at b (file:///D:/tools/LightTable/core/node_modules/lighttable/bootstrap.js:23765:14)
    at Function.eval (file:///D:/tools/LightTable/core/node_modules/lighttable/bootstrap.js:29963:157)
    at c (file:///D:/tools/LightTable/core/node_modules/lighttable/bootstrap.js:6196:14)
    at a (file:///D:/tools/LightTable/core/node_modules/lighttable/bootstrap.js:6236:18)

[s-trooper]

i get same error with 0.6.7. it's occurs only when i am on the last line in python file and the line is empty, line above or not empty and Ctrl + Enter work.