Browser Preview not working

[oldgustav (Gary Loch)]

When I click Preview or do a Command P, I get a ‘Failed to open page’ message in the Safari and this:

Note the suffix in the url. This is on the iMac installation. On the MacBook the same project file previews in the Safari perfectly. Any ideas? TIA.

[dan]

Does it help if you switch off this option off in Safari:

[oldgustav (Gary Loch)]

Dan, thank you! Sorted!