Selenium IDE gives error
"table view is not available with this format" when launched with the new version of
FireFox 55.0.3 (64-bit).
The answer is simple. From
Firefox version-55 onwards, Selenium IDE will no longer available to work.
Refer the latest update on seleniumhq.
As others have mentioned, the IDE only works with Firefox 54 and previous.
So the solution is to downgrade to Firefox 54. But instead of downgrading to Firefox 54, better use Firefox PORTABLE 54.0.1. To keep yourself secure, install Firefox 54 portable just for automated testing with the Selenium IDE and install the portable version of Firefox in a separate directory from your main Firefox. This way you can keep auto-updates on for your regular Firefox. This makes sure you are safe when browsing the web.
And once you have done this, there is another issue to overcome: For some reason the IDE is marked as compatible with Firefox up to 34 only - even so it works just fine in Firefox 54. So the Mozilla addon website prevents the install for now good reason :-(
Solution for this issue:
Download the latest version of the XPI from a 3rd party website, for example from https://a9t9.com/howto/getseleniumide (this is safe, as the XPI is signed)
Drag the XPI on the Firefox 54 window - done!
Or try the new chrome-based selenium ide and give the authors some feedback.