I have looked around on the Steam users fourms and tried to find my answer there but I haven't seemed to have found the answer to my problem, at least one that actually works.
This is a recent problem as my Steam was working fine on the 8th of this month, then on the 9th (Yesterday) I came across an error saying that my Steam could not work unless connected to the internet (Which I am, because I wouldn't be asking this question) so I did a system restore to an earlier date where Steam was working fine, I try to go on it now and it mentions "Updating Steam..." then it fails after like 10 seconds of saying that coming up with the error that is the question title (SteamUI Localization file) I have done what others have tried (Delete the SteamUI.dll and ClientRegistry.blob) deleting them both has done nothing and gave me the connection error problem.
How do I fix this? people have gotten this error before and did what others have said and it works for them.
I'm really confused, I would admire some help if possible.
I had this error aswell. I found no fix but a good solution would be to copy/cut your steamapps folder out of the steam install. Then uninstall steam, erase the steam folder and reinstall. You should then place the steamapps back into the steam install.
Hope this helps (Wish the error didnt exist)
Had the same problem following the latest Steam mega-update, and all I could find was the registry entry fix that wasn't a problem. Deleting that file seems to have fixed it! Thanks! It was located at C:Program FilesSteamsteam.dll for me.