Answered
firefox.exe is not a valid Win32 application
Has anyone had this?
"firefox.exe is not a valid Win32 application"
This warning comes up when Dreamweaver needs to open Firefox.
Edit > Preferences > Real-Time Preview.
Click the plus sign to choose a new browser.
On my system, it's located in Program Files (x86) > Mozilla Firefox > Firefox.exe.
Once again your helpful.
I already had added Firefox to my list.
However, what has fixed it, was removing and reinstalling Firefox.
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