Warning: DevTools failed to parse SourceMap

Environment

• Ubuntu 19.10
• Chromium 80
• Adblock Plus 3.8

From report in forum:

• Windows 8.1 (Build 9600)
• Chrome 80.0.3987.132 (Official Build) (64-bit) (cohort: Stable)
• Adblock Plus 3.8

How to reproduce

1. Install extension.
2. Open JavaScript console for background page.
3. Go to example.com.
4. Open JavaScript console for example.com.

Observed behavior

After 2) Warning shown:

DevTools failed to parse SourceMap: chrome-extension://cfhdojbkjhnklbpkdaibdccddilifddb/lib/adblockplus.js.map

After 4) Warnings shown:

DevTools failed to parse SourceMap: chrome-extension://cfhdojbkjhnklbpkdaibdccddilifddb/include.preload.js.map
DevTools failed to parse SourceMap: chrome-extension://cfhdojbkjhnklbpkdaibdccddilifddb/include.postload.js.map

Expected behavior

No warnings are shown.

Further information

• The referenced source map files exist and look fine on first glance.
• The problem can be traced back to at least 3.4 and cannot be reproduced on Firefox so this appears to be a regression in Chrome.