Zerobrane: fractal-samples: zplane.lua is exiting with an error

I tried out some of the samples coming along with ZeroBraneStudio. spirograph-samples are working fine. May be there should be also a wait() statement at the end of the livecoding-samples and the fractal-samples. Otherwise the graphic window disappears at the end of execution. For fractal-samples: zplane.lua I get an error:

Zoom: {1}
Cent: {0,0}
Area: {-2,2,-2,2}
/Applications/ZeroBraneStudio.app/Contents/ZeroBraneStudio/bin/lua.app
/Contents/MacOS/lua: ./fractal.lua:123: attempt to index local 'C' (a nil value)
stack traceback:
./fractal.lua:123: in function 'Draw'
..ts/ZeroBraneStudio/myprograms/fractal-samples/zplane.lua:103: in main chunk
[C]: at 0x00001c80

Solution

In my version of fractal.lua there is no reference to C variable on line 123. I'd try a newer version, as I don't see any issue with the execution of zplane.lua with the current version of fractal.lua.