Q: Why aren't my login scripts being run automatically and or or showing an error message (admin)?

Answer

Here are two possible answers for the admin:

Note: Users see: Why aren't my login scripts being run automatically and/or showing an error message (user)?

If scripts don't run at all, they might be assigned to the user as logon scripts (in the "User Configuration" section of the Group Policy) without the GPO Loopback option to be set to replace in the assigned Group Policy. Generally, we use startup scripts not login scripts (in the "Computer Configuration" section). It is also possible that permissions on the Group Policy object restrict to whom these policies apply--either through Security Groups or WMI filters.
There are a number of other possible options for failure to run the logon/startup script. For example, it could be insufficient access to the script files as well as incorrect paths being specified. Lastly, if it's a custom script, it is possible that there are syntax errors in the code that prevent it from running, or command files referenced that are not in the correct location or do not exist at all (e.g., Active Perl, Mirror Distrib folder).