Hello!
What happened in version 10.0.0.3920 that pressing: alt+l causes right alignment? I have a Polish keyboard and I use the alt+l keyboard shortcut for Polish characters. Now I can’t do it because when I press alt+l the text aligns to the left. Please help!!!
same problem with z ALT+c - in Polish
As a first troubleshooting step, can you please try uninstall Axure RP 10 and rolling back to a previous version to see if that helps?
You can do so by navigating to our release history page linked below:
If you need to roll back to a version before build 3916, then you can use the link below or change the URL to match the build:
https://axure.cachefly.net/versions/10-0/AxureRP-Setup-3915.exe
I have the same issue. You can workaround pressing Shift + Alt + L for uppercase Ł or the same with caps lock for lowercase ł. 
Możesz też przeklejać teksty z innego edytora, obejść jest dużo ale wolał bym jednak tak bez kombinowania 
I also have Axure 9 installed and there is no problem with alt+l.
But I have to work on Axure 10 because I have a group project there.