Hi friar John, thank you for reporting, I’ll take a look immediately, and will have a repaired version released very soon.
In the meantime, if you would like to downgrade back to version 2.8, you can do so by replacing your directory: /wp-content/plugins/device-theme-switcher/ with this one: https://downloads.wp.xz.cn/plugin/device-theme-switcher.2.8.zip
More info: Now that I am thinking about it, I could have really ‘confused’ WordPress when I upgraded WordPress (to 4.1) on another computer than the one I was logged onto previously and never logout. Both computers were desktop styles. On the same computer I upgraded to 4.1, I then began to update the plug-ins needing to be updated. Once I got to Device Theme Switcher I believe it never went back to the general listing of plug-ins (page).
— friar John
Any suggestion of how to get my WordPress site up and running again. I am pretty much an amateur at fixing downed websites.
Hi again friar John,
This issue has since been corrected in the newly released version 2.9.2.
If you have not yet removed the broken plugin, please replace your directory: /wp-content/plugins/device-theme-switcher/ with this one: https://downloads.wp.xz.cn/plugin/device-theme-switcher.2.9.2.zip
Thank you. Up and running again.
For anyone stumbling across this thread. This issue only occurred for users with PHP < 5.3. Please update to the latest version of this plugin to correct the issue. Thanks!