UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:59.0) Gecko/20100101 Firefox/59.0

Steps to reproduce the problem:
1. Have target instance available with remote-debugging-port set
2. Go to chrome://inspect
3. Click "Inspect" for desired target

What is the expected behavior?
Dev Tools open and connect to remote target

What went wrong?
Window opens with Chrome error message:

This site can’t be reached
The webpage at chrome-devtools://devtools/?dockSide=undocked might be temporarily down or it may have moved permanently to a new web address.
ERR_FAILED

Did this work before? Yes 65

Chrome version: 66.0.3359.139  Channel: stable
OS Version: 10.0
Flash Version: 29.0.0.171

Using the bisect-builds tool, I arrived at the following result:

You are probably looking for a change made after 535635 (known good), but no later than 535645 (first known bad).
CHANGELOG URL:
  https://chromium.googlesource.com/chromium/src/+log/e04a14f4769d6b33b32686ccc3414e917a625ae7..004f3b4b4000be325307d1c409a03411aa00beaa

The issue occurs with Chromium on Linux (same version), too.