Hey,
I know I'm 3 years late here, but I retested this on 5.2.1, still getting the error.
Here's the solution:
I managed to avoid the issue with synchonized():
def tc = testRunner.testCase.testSuite.testCases["callee"]
synchronized(tc){
def runner = tc.run(null, false )
}
Run a couple of times for a minute with Load Test set to Simple Strategy, 0 Test Delay and 0 Random. I got around 5mil executions per minute, zero errors.
Same setup, but not synchronized, rolled off 10k rows error log in 3 seconds, getting spammed with the one you got:
ERROR:groovy.lang.MissingPropertyException: No such property: context for class: Script1
Hope this helps :)
Jakub