Scratch - Error out of memory!!

Was siting down with my 5yr old trying to blink some LEDs using scratch.
Repeat x times doesn't seem to work
Also looks like scratch code is run async?
if so it's not something I can teach my kid I struggle myself!
Would be good to see the js code that scratch creates.

Anyway in my floundering around (image attached) I got this

ERROR: Out of Memory!
ERROR: Out of Memory!
WARNING: Unable to create string as not enough memory
ERROR: Out of Memory!
WARNING: Unable to create string as not enough memory
ERROR: Out of Memory!
WARNING: Unable to create string as not enough memory
ERROR: Out of Memory!
WARNING: Out of memory while appending to array
ERROR: Out of Memory!
at line 5 col 17

 }, 2*1000.0);
             ^

in function called from system
Execution Interrupted during event processing - clearing all timers and watches.

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