Chrome Version (from the about:version page): Version 52.0.2743.82 Built from source for Fedora release 23 (Twenty Three) (64-bit)
Is this the most recent version: nearly
OS + version: Fedora 23
CPU architecture (32-bit / 64-bit): 64
Window manager: xfwm4
URLs (if relevant):
Behavior in Linux Firefox: works
Behavior in Windows Chrome (if you have access to it): works

What steps will reproduce the problem?
(1)  Set default browser to Chromium in "Preferred Applications" -or-
(2)  Set default browser within Chromium
(3)

What is the expected result?  http(s) URL handlers work from other programs


What happens instead? I/O error on click.  It doesn't seem to be signaling the existing Chromium process to open a new wi
ndow/tab, but it looks like it's trying to create a new chromium process


Please provide any additional information below. Attach a screenshot
and backtrace if possible.

UI: "Failed to execute default Web Browser. Input/output error."

exo-open: Failed to create a ProcessSingleton for your profile directory. This means that running multiple instances would start multiple browser processes rather than opening a new window in the existing process. Aborting now to avoid profile corruption.


$ exo-open --launch WebBrowser
[3335:3335:1024/093800:ERROR:process_singleton_posix.cc(273)] Failed to create /home/.../.config/chromium/SingletonLock: File exists
[3335:3335:1024/093800:ERROR:chrome_browser_main.cc(1516)] Failed to create a ProcessSingleton for your profile directory. This means that running multiple instances would start multiple browser processes rather than opening a new window in the existing process. Aborting now to avoid profile corruption.

$ chromium-browser
[3968:3968:1024/093819:ERROR:process_singleton_posix.cc(273)] Failed to create /home/.../.config/chromium/SingletonLock: File exists
[3968:3968:1024/093819:ERROR:chrome_browser_main.cc(1516)] Failed to create a ProcessSingleton for your profile directory. This means that running multiple instances would start multiple browser processes rather than opening a new window in the existing process. Aborting now to avoid profile corruption.

$ exo-open http://www.chromium.org
$ [4464:4464:1024/093844:ERROR:process_singleton_posix.cc(273)] Failed to create /home/.../.config/chromium/SingletonLock: File exists
[4464:4464:1024/093844:ERROR:chrome_browser_main.cc(1516)] Failed to create a ProcessSingleton for your profile directory. This means that running multiple instances would start multiple browser processes rather than opening a new window in the existing process. Aborting now to avoid profile corruption.

$ chromium-browser http://www.chromium.org/
[4985:4985:1024/093908:ERROR:process_singleton_posix.cc(273)] Failed to create /home/.../.config/chromium/SingletonLock: File exists
[4985:4985:1024/093908:ERROR:chrome_browser_main.cc(1516)] Failed to create a ProcessSingleton for your profile directory. This means that running multiple instances would start multiple browser processes rather than opening a new window in the existing process. Aborting now to avoid profile corruption.