Question

I'm trying to deploy/retract my solutions but they seem to be stuck in the "Deploying (scheduled for 12:00am)" status but it doesn't seem to be doing anything. What do I do?

Answer

The issue you are experiencing may be caused by either your SharePoint admin service or SharePoint timer service not being on. This is especially common in farms that have multiple servers as the services may be off for some of the servers. You will notice that this behaviour will affect all custom solutions and not those belonging to KWizCom. To overcome this issue, you will want to try the following steps:
-Cancel the deployment/retraction for the solutions
-On each of your web front end servers, check to see if your SharePoint admin service and SharePoint timer service is running
-Restart the SharePoint timer service on each web front end server
-Attempt the deployment again

If you still experience issues, you may need to do the deployment/retraction manually using PowerShell via the following commands:
To deploy the solution use the install-spsolution command with the local and force tags. You will want to do this for each solution on each web front end server:
-Install-SPSolution -Identity solution_name.wsp -GACDeployment -local -force
Additional information on how to use this PowerShell command can be found here: https://docs.microsoft.com/en-us/powershell/module/sharepoint-server/install-spsolution?view=sharepoint-ps

To retract the solution, use the uninstall-spsolution command with the local and force tags. You will want to do this for each solution on each web front end server:
Uninstall-SPSolution -Identity contoso_solution.wsp -local -force
Additional information on how to use this PowerShell command can be found here: https://docs.microsoft.com/en-us/powershell/module/sharepoint-server/uninstall-spsolution?view=sharepoint-ps
After doing that, you can then just remove the solutions from the central administration.

The issue may actually be related to an issue with your farm rather than the solutions themselves. Some additional resources online which you may want to check regarding this issue can be found here:
http://www.matt-thornton.net/tech/sharepoint/sharepoint-solutions-stuck-retracting-deploying
https://social.technet.microsoft.com/Forums/office/en-US/b2e80cd1-3dcc-42df-9149-143161615362/wsp-is-stuck-in-deploying-state?forum=sharepointadmin