First:

WebApp Config
Invalid web server: [varying_text]
Error: -2147024893
Followed by:

ERROR: Failed to configure Enterprise Vault web app, error: 5
This issue is caused by the space in the password (circled). Even with the password placed in quotes, the script does not parse it correctly. (You can see in the example that it thinks the second half, "word," is a web server argument.)
Other characters that cannot be used in the password for this account include ^ and &.
The simplest solution is not to use a password with spaces or other prohibited characters in it for this account.

Alternatively, if you must use a password with characters prohibited by the script, you can do the following:
1. Add the switch "/skipverify" to the end of the script command.
cscript owauser.wsf /domain:ev8 /user:evanon /password:pass word /skipverify
2. After the script finishes successfully, open IIS and manually enter the credentials for the anonymous account on the Authentication Methods page of the EVAnon virtual directory properties. The field here will accept characters, such as spaces, that the OWAUser.wsf script will not.
IIS Manager > Web Sites > Default Web Site> EVAnon > Properties > Directory Security tab > Authentication and access control > Edit... > Use the following Windows user account for anonymous access: