& can't be encoded, how to upgrade to v5 alpha?

[kopax]

I am having an issue when params in url are using special char such as percent, the encoding is failed. I have opened the issue here but I think this would be the right place.

I have seen in the changelog that a v5 alpha is now up and it seems from the changelog that this issue may be fix.

However, I was not able to upgrade without issue, this is the error I have when trying to change from the entrypoint to another route:

Could not find router reducer in state tree, it must be mounted under "router"

I can see that my reducer is well initialized for history v4.10.1 and react-router 5, how can I perform the upgrade without hassle ?