If you want to report an error with the online version of Twine in some browsers, then the Twine “Issues” page on GitHub is the place to do that. (I don’t normally use the online version, so I don’t know what might cause that error.)
That said, since you’re not on a mobile device (smart phone, iPad, etc.), it’s generally better to download and use the offline version of Twine. That should prevent any problems with publishing.
I’d recommend seeing if you can use the “Archive” button in the online version of Twine to create an archive of your current work, then use the “Import” button in the offline version of Twine, and import that archive, that way you can pick up where you left off.
Also, other than for testing purposes, I’d recommend against using any version of IE, if you can, since it’s pretty badly outdated. The current version of Edge is basically a reskinned version of Chrome, so that should work fine.
And yes, it’s completely normal for new passages to contain nothing but “Double-click this passage to edit it.” in it. It’s up to you to add whatever content you want to those passages, and since normally it won’t be the same as any other passage, there’s no way for the Twine editor to know what else to put there.
Any “instructional text” would vary depending on what story format you use within the Twine editor. I’d highly recommend using the SugarCube story format, due to its ease of entry, flexibility, breadth of sample code, and suite of built-in tools. That link will take you to the SugarCube download (if you want the latest version) and documentation. You can select the story format you’re using in the main Twine editor window to set the default story format (Twine defaults to the Harlowe story format), or within any particular story to set the story format for that particular story.
Hope that helps!