F12 stoped working

[Scott449]

it was working fine then just stopped, I just get a page that says

"You tried to access an external HTML page, which can not be opened on the device for preview. Open the page in Dreamweaver to preview the page on the device." 

I looked through the help files in this forum and most suggest that I use the "open in browser" command and that does work but it is not the same function as the live preview.

any ideas I am using 20.1 on win 10

[Nancy OShea]

Real-Time Preview is hit & miss.  Sometimes it works, sometimes it doesn't.  I've found it won't play nice with my local testing server so I turned it off in Preferences.  Old fashioned Preview in Browser works every time. 

That said, a few things you can try:

1. Restart your computer. Open a valid HTML document.  Hit F12.

2. Restore Preferences.
https://helpx.adobe.com/dreamweaver/kb/restore-preferences-dreamweaver.html

3. Contact technical support via online chat.

https://helpx.adobe.com/contact.html

[Scott449]

ya finding that too  Real-Time Preview is a really useful feature.

[Jon Fritz]

Are you working from within a Defined Site and is that site definition selected in the Files window?