SYMPTOM:
Edit menu for some Report Services Documents is disabled in Strategy Developer 10.0 to 10.5.
CAUSE:
The change was by design. In Strategy Analytics platform 10.0 to 10.5, multiple Web new features were introduced in Web, but not supported by Developer. To reduce the risk of any inconsistent behavior within the document definition created in Web, Edit menu was disabled in Developer for documents which contain such 10.x Web new features.
Examples of such new features introduced in Strategy Web 10.x:
Documents containing such features will be marked as 10.x version documents in the backend. And, Edit function was disabled in Developer for such 10.x version documents.
Strategy realizes that customers do need Edit function in Developer for such documents, because some general functionalities are not available in Strategy Web. For example, document cache could be enabled or disabled at document level in Developer but this functionality is not available in Web:

So staring from 10.6, Strategy exposes Edit in Developer again for documents with 10.x Web new features. Please note the following scopes:
Here are some examples that 10.x Web new features are not supported by Edit in Developer:
It is required to edit 10.x Web new features and its related functionalities in Web. And there will be a warning message pop up in Developer when user attempts to edit 10.x version document in Developer.
ACTION:
Upgrade to Strategy 10.6 to take advantage of new release.
The Strategy Internal Reference Number for the issue discussed in this technical note is: DE32775 / DE36585, DE36084, DE41481 / DE41565, DE44451.