I used the "MonkeyC: New Project" option to create a new data field, then changed the compute function to
function compute(info as Activity.Info) as Numeric or Duration or String or Null { // See Activity.Info in the documentation for available information. return -507453934; }
then exported it, and tried to upload it as a beta app. I got:
The following errors were detected in your app file
- Signature check failed.
Basically, this happens if the number -507453934 shows up anywhere in your app.