Managed installed classes cannot be saved(Tooling API)

Question

I am creating an App in which there is tab in the App with a Visualforce Page. But it will show a nothing on start(Empty Page with just apex:page markup) and after setting up a some configurations of the App the Visualforce Page content needs to be updated. But when I try to install the package as the App in Dev it throws the Error "Could not save TestPage, : managed installed classes cannot be saved". However it is getting updated in the Packaging Org. I am using Tooling API to update the Visualforce Page.

This is the Response from the containerAsyncRequest:-

{
  "attributes": {
  "type": "ContainerAsyncRequest",
  "url": "/services/data/v38.0/tooling/sobjects/ContainerAsyncRequest/1dr0Y00000168j7QAA"
  },
  "Id": "1dr0Y00000168j7QAA",
  "IsDeleted": false,
  "CreatedDate": "2017-02-18T15:01:08.000+0000",
  "CreatedById": "0050Y000000SpFtQAK",
  "LastModifiedDate": "2017-02-18T15:01:08.000+0000",
  "LastModifiedById": "0050Y000000SpFtQAK",
  "SystemModstamp": "2017-02-18T15:01:08.000+0000",
  "MetadataContainerId": "1dc0Y0000001SoBQAU",
  "MetadataContainerMemberId": null,
  "ErrorMsg": "Could not save TestPage, : managed installed classes cannot be saved",
  "IsRunTests": false,
  "State": "Failed",
  "IsCheckOnly": false,
  "DeployDetails": {
    "allComponentMessages": [],
    "componentFailures": [],
    "componentSuccesses": [],
    "runTestResult": null
  }
}

Answer 1

It looks like you are trying to use the tooling api to dynamically update a managed package component in the subscribers org. That isn't possible. As you found, components of a manged package can only be updated in the packaging org.

It's the same general idea as the subscriber org not being able to update the components.