As other bloggers have noted the interface for writing these posts has been ‘upgraded’ - the new interface has a few glitches shall we say. For example ‘preview’ doesn’t work unless you disable your pop-up blocker, and let’s not get started on positioning photos.
The temporary fix is to click ‘Revert to legacy Blogger’ on the bottom left of the screen (or in the drop-down menu on an iPad). This will work until August 24 when this option will be taken away and we’re forced to use the new interface - hope it improves by then!
So this is the important bit: once you have clicked ‘Revert to legacy Blogger’ go to the address bar, copy the address into notepad* and save it. In most cases the legacy interface isn’t deleted - just our access to it is removed - we can use the saved URL to access it.
* Bookmarking it probably won’t work - may need some tinkering.