When an advanced report is exported as '.PPTX' format in IE11, and you try to edit the PPT report you get the following messages.
Therefore, you are unable to edit this exported report.
CA PPM 188.8.131.52.0.6 (Service Pack 6 applied)
Browser Internet Explorer 11.1029.15063.0 (Portuguese BR and English version were tested)
This behavior only occurs on the scenario below:
1- Internet Explorer browser
2- From the choices presented, the 'Open' should be selected;
For that reason the source of this behavior is mixed, between IE security properties adjusted by the environment and the configuration inside the Power Point.
To solve the presented behavior, you could check the IE security properties (allowing downloads files) and from Power Point, disable the option 'Enable Protected View for files originating from Internet'.
Any other ways to edit the exported advanced report as PPTX format, will avoid the issue: Use other browsers, executing download the report before editing it.