[Dvipng] Path error with dvipng under Windows 10

[Johan Andberger]

Hello

I'm having issues with using dvipng 1.15 under Windows 10, when I try to 
execute:

dvipng "-q" "-bg" "Transparent" "-T" "tight" "-o" 
"c:\users\johana~1\appdata\local\temp\zim-Johan%20Andberger\equation.png" 
"c:\users\johana~1\appdata\local\temp\zim-Johan%20Andberger\equation.dvi"

I get:
dvipng: Fatal error, unacceptible format spec in output file name

However, if I change the output path to e.g. 
"c:\users\johana~1\appdata\local\temp\equation.png" it works. I don't 
know if the issue might be the % sign in the path or something else, is 
there some workaround for this?

I'm getting the issue because I'm using the Equation editor plugin for 
Zim (http://zim-wiki.org/).

I would be thankful for any assistance.

Kind regards

Johan