Missing SID warnings

[veonone]

Hi,

We are running Plesk over a Windwos 2012 R2 that is not apart of any domain. Running ApplySecurity for a folder results in some warnings about the following SIDs.

"MSSQL$SQLEXPRESS MSSQL$MSSQLSERVER2014 IWAM_coldfusion8 IWAM_coldfusion9 IWAM_coldfusion10 IME_SYSTEM seuser psaagent IWAM_coldfusion8 IWAM_coldfusion9 IWAM_coldfusion10"

I managed to get rid of most of them by creating these users but I cannot do it for MSSQL ones. Should I be concerned? Can I remove them from DiskSecurity? Why is Plesk creating permissions for these users? I did not yet see any functionality issues with them missing.