We just encountered this error for the first time today. The situation was similar, but not exactly the same.
A couple of weeks ago, an admin changed a native application using the smart dashboard. It was noticed some time afterwards that the native application was not working right. Over several days, other changes were made to the native application in an attempt to address the issue which culminated today in the 1-4000018 error. All these changes were made in Smart Dashboard.
After googling the error and reading this community article, the native application was examined in SmartConsole. The Allowed Locations Advanced settings were found to be blank, even though they looked fine in Smart Dashboard earlier.
The native application was updated in SmartConsole, the update was published, and the policy push was then successful. However, after that, other admins who were already in SmartConsole still found that native application's allowed locations to be blank. Each had to exit and re-start SmartConsole before the native application appeared correctly with the correct allowed locations.
We are using R80.40 HFA take 118 on both management and gateways