Removed Farm solutions using (Remove-SPSolution) are still showing inside my site collection "Site features"

Question

I am working on deploying an event receiver inside my sharepoint 2013 sites using visual Studio. now i deploy the farm solution using visual studio successfully. Then i wanted to remove the farm solution completely. so i login to the sharepoint hosting server and i run the following command:

Remove-SPSolution -identity "cmorit_2.wsp"  -force

the command completed without any problem. and the solution disappear from "Central Administration >> System settings>> Manage Farm solutions". so i thought everything is fine.

but i am facing these 2 problems:-

1. the feature name are still showing inside my site collections "manage site features" section, and i can active it , as shown below:-

2. also i did some modifications to the event receiver inside Visual Studio and i deploy it again , but i got this error :-

Error 1 Error occurred in deployment step 'Add Solution': A feature with ID 15/ac3d38f9-49f6-4638-a65b-d15a8bbe40c2 has already been installed in this farm. Use the force attribute to explicitly re-install the feature. 0 0 CMorIT-2

so did the Remove-SPSolution actually remove the SPSolution!! as seems it is still their .

Answer 1

Completing removing a solution requires two steps:

1. Retracting the solution (can be done from the the CA, or with Uninstall-SPSolution)
2. Removing the solution (also, can be done from the CA, or with Remove-SPSolution

Using Remove-SPSolution -force as you did leaves your farm in a corrupted state where the solution is still activated (actually the correct term is "deployed" or "installed").

Also, even before removing a solution with the two steps above, you still need to disable (deactivate) all features on all sites it had been activated. Failing in doing so would also leave your farm in a "corrupted" state where some features are orphaned.

Visual Studio usually does all this for you (and this is a very bad thing, coz you don't know what it does exactly, and sometimes it also performs manual tasks in the hive, but that's another story).

In your current situation, I would try to add the solution back to SharePoint with a Add-SPSolution, then Install-SPSolution -force: that would overwrite features it's currently complaining about.

[EDIT]
Deactivating the feature everywhere it was activated is NOT done automatically by Uninstall-SPSolution: you have to do it "manually" everywhere the feature is activated (this can be done by a script as well).
However, if you only remove the solution to immediately add it back (instead of using Update-SPSolution), and the new version contains the same exact features, you don't really need to deactivate the features, as they won't be orphaned anymore when the solution is back online!