I haven't seen an NSIS error before, but google seems to think it could mean a damaged/corrupt executable. Have you tried redownloading Steam?Ended up reformatting SSD and reinstalling Ubunutu. Spent past two nights trying to get Elgato cap card to work. Never did work though, just didn't compile how all the tutorials did. Probably cause I am using a different version of Ubuntu. Also tried Listro and it kept hanging on me while trying to Install T7. Don't know what I did wrong but hopefully the reformat helps. Got really familiar with terminal the last 2 nights. Going to have to research how to use WINE. Listro seems to confusing for what ever reason, I also dont want to create an account to manage a library .
EDIT: Unable to install Steam via WINE. GET NSIS Error. Giving up for the night. Any advice would be nice. :'(
Alternatively, I would recommend using Lutris or PlayOnLinux to manage the download and installation of the Windows version of Steam. The only thing you need an account for in Lutris is to download scripts which automate any wine configuration.
I can offer more help soon, but right now I am away from my Linux machine which is making advice difficult.