History missing hash in URL for some users

[chris@umed.io]

I have implemented the History functionality built into SmartClient and works for most of the users but there are a few who get this error in the browser (exact same deployment that works for well over 80% of users):
[HTML]VM9662 ISC_Core.js:1283 *18:24:51.745:XRP6:WARN:History:Unable to fire history callback onhashchange from: https://x.y.com/some/uri/#1 to: https://x.y.com/some/uri/ - reason: no hash in newURL[/HTML]

When watching a screen recording, there is no hash with s numeral added to thise users URLs as they navigate.
It is not clear to me how this hash gets added so any pointers on where to look to identify the cause would be helpful.

If it helps, this seems to occur on Microsoft Windows based computers as it cannot be replicated on OSX or Linux and for the most part on Microsoft Windows based computers..
The only indication something went wrong is the above WARN message and there is no obvious pattern regarding browser and the user is able to use the application as normal apart from the History function

[Isomorphic]

See History docs - you register particular states with the History engine, giving them IDs and we add them as hashtags.

This sounds like maybe you passed a null ID at some point - it's unclear. Let us know if you can show how to reproduce this.

[chris@umed.io]

It turned out that we were invoking the history call before the page had completely loaded as specified in the docs and I guess slower machines were affected. thanks for the guidance.