Hi,
You need to check the 'Additional information' sections of the error you get. It contains information on the reason of this error.
Yes, we recommended that you read the "Handling the 'Object Not Found' Errors" help topic because it contains a step-by-step instruction on troubleshooting 'object not found' errors along with possible solutions. There's no "magic medicine" for this problem. Anyway, you need to check your test and logs, check your application's objects and correct your code.
I'd start with checking whether the target object's name is correct and
waiting for this object.