I have Windows 7 and maybe is that the reason for crashing when i start it?

I have win7 too. Is there any error message?
Edit:
Try installing this https://www.microsoft.com/en-us/download/details.aspx?id=34595
Edit:
Or use the other executable which is included now.

ERROR: The running command stopped because the preference variable "ErrorActionPreference" or common parameter is set to Stop: Cannot find path 'C:\Program Files (x86)\Steam\steamapps\workshop\content\497180\1260638035' because it does not exist.

Thanks for reporting! It is fixed now.

When I try and download the mod, this error comes up.

System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'InstallForm'.
at System.Windows.Forms.Control.CreateHandle()
at System.Windows.Forms.Form.CreateHandle()
at System.Windows.Forms.Control.get_Handle()
at System.Windows.Forms.Control.SetVisibleCore(Boolean value)
at System.Windows.Forms.Form.SetVisibleCore(Boolean value)
at WorkshopInstaller.InstallForm.LoadForm()
at CMainModule.m_bManageWorkshopItem(CMainModule* , Int32 index)
at WorkshopInstaller.ManagerForm.ActionButton_Click(Object sender, EventArgs e)
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Did you mean you tried installing the Custom Workshop Installer with the stock intaller?
If installing it with the stock intaller doesn't work, install(copy/paste) the files manually - see "How to use" section.

I just subscribed to this and windows instantly flagged it as a trojan,

"This program is dangerous and executes commands from an attacker"

Yep, nothing new
https://psteamcommunity.yuanyoumao.com/workshop/filedetails/discussion/1445498636/3185740658294761312/
Apparently there is some proof of concept hack made with the same converter used here, and now, it seems, everything created with that converter gets flagged.

item names file not found: _CustomWorkshopInstaller_ItemNames pls help
EDIT ( I forget the other download file)

I subscribed to this mod and BitDefender Antivirus instantly flagged it as a trojan.

Details:
"The file D:\SteamLibrary\SteamApps\workshop\downloads\497180\1445498636\_CustomWorkshopInstaller.exe is infected with Gen:Heur.MSIL.Krypt.11 and has been moved to quarantine. It is recommended to run a system scan to make sure the system is clean."

It appears that BitDefender had detected quarantined the file until this matter can be resolved. I'm not sure whether or not antivirus is happy about this...

See my previous reply. Not much I can do about it.

Thanks for advice.