On Tue, Sep 20, 2016 at 3:50 PM Kaushal Modi <kaushal.modi@gmail.com> wrote:

>
> I'll update this thread with new findings.
>

I haven't yet been able to recreate that block highlight. But here I get a
similar highlight on a string, with flyspell mode off. I also switched from
the default major mode verilog-mode to fundamental mode. And even then I
get that highlight.

Here is the result of C-u C-x =:

http://i.imgur.com/Nx0hPmX.png

I do not understand overlays very well, but it looks like verilog-mode or
some minor mode created 5 overlays over the same region, and they did not
get removed even when those modes were disabled.
-- 

Kaushal Modi