I use latest 64-bit version of Calibre on Win10 PC.
I've known for a while that if you get a parsing error (tag imbalance) that sometimes a black diamond with question mark shows in the text. This does not happen with every parsing problem, not sure what causes this to appear.
This time, I had something really weird happen, that I've never seen before.
The file I was practicing with obviously had some processing problems from previous editor: some word spacings were deleted where they shouldn't and two words were stuck together in many locations. I only noticed that this early in the editing process (spelling check usually is my last step) because that is where the black diamonds showed up.
What caused the black diamonds to appear: I deleted the initial span-tag at the top of the page. This caused parsing error, and the diamonds appeared (Pic1)
The black diamonds showed only in the preview screen, not in the editor screen. Because the diamonds do not appear in the editor screen, I cannot search for them. When I find one in preview and push delete button in the corresponding editor position, the cursor does not advance, but the black diamond in preview disappears.
Even stranger, when I used 'auto correct errors' (which just deletes the superfluous end tag and removes the error, which normally makes the diamonds disappear) the diamonds not only stayed in preview, but also appeared in the editor (Pic2) And because they did show in the editor now; I was able to use the editor to get rid of them all at once.
I have attached the file that showed this problem. It is an incomplete (less than 1 chapter) extract from a book that I use for self-education practice with the editor. The diamonds appear by removing the initial span tag after the title.
They stay even when the final closing tag is removed.
QUESTIONS:
1. Why do those diamonds only appear in a (very small) minority of files with parsing errors, not in others even though they may have similar errors.
2. What's up with the invisible character? Before today, if they showed, these diamonds always showed in both editor and preview screens. This is new. Not only invisible, but also not taking up any space in the editor? Is that possibly a bug?
Comments invited and appreciated.