NSE: failed to initialize the script engine: - lua

Question

I'm new to VAPT and I'm using GUI for windows, this is what I got when I used this script from nmap online guide [nmap -p 80 --script http-default-accounts.routers xx.xx.xx.xx]. I borrowed the script from here : https://nmap.org/nsedoc/scripts/http-default-accounts.html
[nmap -p 80 --script http-default-accounts.routers xx.xx.xx.xx]
Nmap output begins below this line:
NSE: failed to initialize the script engine:
C:\Program Files (x86)\Nmap/nse_main.lua:823: 'http-default-accounts.category' did not match a category, filename, or directory
stack traceback:
[C]: in function 'error'
C:\Program Files (x86)\Nmap/nse_main.lua:823: in local 'get_chosen_scripts'
C:\Program Files (x86)\Nmap/nse_main.lua:1315: in main chunk
[C]: in ?
QUITTING!

Answer 1

Nmap uses the --script option to introduce a boolean expression of script names and categories to run. To provide arguments to these scripts, you use the --script-args option. So what you wanted to run was: nmap --script http-default-accounts --script-args http-default-accounts.category=routers
In most cases, you can leave the script name off of the script argument name, as long as you realize that another script may also be looking for an argument called category. For example: nmap --script http-default-accounts --script-args category=routers

Answer 2

If you are using this command:
nmap --script vulscan.nmap-vulners -sV {target}
Then use the following command instead.
nmap -sV --script vulners {target}
For me, it worked.

Answer 3

As for Nmap 7.90 [2020-10-03] changelog, dealing with directories has changed:
[GH#2051]Restrict Nmap's search path for scripts and data files. NMAPDATADIR, defined on Unix and Linux as ${prefix}/share/nmap, will not be searched on Windows, where it was previously defined as C:\Nmap . Additionally, the --script option will not interpret names as directory names unless they are followed by a '/'. [Daniel Miller]
So basically if we said you are using kali and this is your old command:
nmap --script vulscan -sV ###.###.###.###
It should become like:
nmap --script vulscan/ -sV ###.###.###.###
adding a / after directory name.