Pinned icon gets duplicated under Windows 10

Operating system: Windows 10 (64-bit).
How to produce the problem: Install IceDragon and optionally make it the default browser (doesn’t matter). (1) Pin Icedragon to the taskbar, then run it; or (2) run Icedragon when it is not pinned, then pin it. In both cases a second icon appears.
Attempts to resolve the problem: (1) Easy Windows 7 workaround ( ) does not work in this case. (2) More complicated workaround ( [Guide] Pin programs with custom launchers to taskbar - Essential Guides - Neowin ) requires software that is not compatible with Windows 10 yet and may or may not resolve the problem when it is done. (3) Another workaround on Windows 7, used by some Cygwin users, involves the manul creation of a .url file in INI format. However, I did not find a way to get a file path involving spaces into a file: url. (%20 doesn’t work.)
Screenshot: Just imagine two IceDragon icons next to each other in the Windows 10 taskbar, one underlined and possibly highlighted, the other not, but otherwise both identical.
Additional information:

[ol]- Windows clearly knows that both icons belong to the same application, since you can use either one to unpin. Either way one icon disappears, the other icon knows it’s unpinned now, and after closing IceDragon there is no IceDragon icon left in the taskbar. Unfortunately, to me this suggests that workaround (2) may not work even when 7+ Taskbar Tweaker becomes available for Windows 10. On the plus side, it also implies to me that Microsoft might consider this behaviour a Windows bug.

PS: My installation history is as follows. I installed IceDragon 38.0.5 recently on a new Windows 7 that didn’t have any flavour of Mozilla. Then I upgraded to Windows 10 and had the problem described. Apparently a Firefox user got rid of the same problem by running the Firefox setup program again after the Windows 10 upgrade. I tried this with IceDragon without success, even when I first uninstalled IceDragon. (I did keep my profile, though.)

Another detail I forgot to mention: Clicking the pinned icon opens a new browser window, which then gets grouped with the other icon(s).

I have this problem also, but Firefox does not do the same.

I lost all my program data when installing W10 as they decided to change my language from English to French because I have a French ip address. I changed it back to English after installing, but had to reinstall my programs and their data.

I lost all my program data when installing W10 as they decided to change my language from English to French because I have a French ip address.

Who did? Firefox? Windows? What an incredibly stupid idea! Fortunately the Windows 10 upgrade didn’t do that to me. My internet provider bought some IP addresses of a country whose language I don’t speak. Since then, I have been having all sorts of fun with websites that try to be intelligent based on old data. This has been going on for a year already.

It was Microsoft. Having already spent a long time downloading the media creation tool they informed me that I had chosen a different language although I had followed the download instructions in English, so I could only keep personal files. My fault for not waiting in the queue.

It’s Microsoft. A similar problem has also been reported by users in the Netherlands.