Important Limitations and Known Issues

Variables Should Not Be Declared inside the Loops

The following code can result in an error message "Too many new instances created" in the server log:

for (...) {
  def var = [:]
}

So you should always change it to this form:

def var
for (...) {
  var = [:]
}

The technical background is that the first script allocates a new variable which can increase the number of FormulaSandbox instances (above the limit).