Old library directory leftovers

IDE: 1.8.9
Windows: 10 US

I am having similar problems as described here

https://forum.arduino.cc/index.php?topic=426443.0

I.e. a directory leftover from a previous installation of a different version of the same library.

I can't say how often it happens but my gut feeling is that it happens 10% of the times I install a newer/older library. I now know what to look for. But I know of cases where others have spent most of an evening/day trying to figure out what the problem is and in the end did a complete uninstall and reinstall of the Arduino IDE before things were back to normal.

Might it be an idea to let the IDE do a check at launch and remove old library directories that don't match the version number in the Board/Library Manager "database" OR allow more than one directory and still use the one that matches the BM/LM DB?

MikD:
in the end did a complete uninstall and reinstall of the Arduino IDE before things were back to normal.

A standard IDE uninstall won't do anything to solve this issue because the Boards Manager installations are made to a separate folder from the Arduino IDE installation, which is not removed when you uninstall. You would actually have to manually delete that folder to fix the problem.

MikD:
Might it be an idea to let the IDE do a check at launch and remove old library directories that don't match the version number in the Board/Library Manager "database" OR allow more than one directory and still use the one that matches the BM/LM DB?

That wouldn't help. The index contains all the version numbers. The only way the Arduino IDE knows which version you installed is by looking at which version folder is present.

I agree that the Arduino IDE could be much smarter about dealing with this issue. If a version folder is empty, it should be either deleted or ignored. At the very least, the IDE could display a more helpful error message

Ah OK. Did not know the inside details of the IDE.

But yes some general housekeeping might be a good idea. I am not to familiar with the feature request procedure so how to do this?

MikD:
But yes some general housekeeping might be a good idea. I am not to familiar with the feature request procedure so how to do this?

We already have a bug report/feature request about this:

However, if you have other features you would like to request or bugs you would like to report which are not already in the issue tracker, they are welcome! The procedure is described in the contributing guide:

You can post your ideas here on the Arduino forum to get some feedback from the community and refine the idea before escalating it to the attention of the Arduino developers in the issue trackers.