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• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for an issue that matches the one I want to file, without success.

Issue Details

• Electron Version:
  • 7.0.0
• Operating System:
  • Windows 10 (1803)
• Last Known Working Electron version:
  • 6.1.2

Expected Behavior

Loading flash content through an swf file results in the correct visualization of said content

Actual Behavior

An error "GET http://interactive-mirror3.nfb.ca/FrameLoader.swf net::ERR_INVALID_ARGUMENT" appears:

To Reproduce

Try embedding this flash website in an electron project (http://bear71.nfb.ca/#/bear71) following this tutorial: https://electronjs.org/docs/tutorial/using-pepper-flash-plugin

Screenshots

Additional Information