Short version: if your landed ship/plane/base/whatever jumps up when you switch to it, this mod might help you. (or might make it worse, who knows)

Longer version:

Some reports suggest that 1.5.1 is affected too...

Although the bouncing bug was almost fixed in KSP 1.4.x, there are still some odd situations where it happens, according to several reports.

There's confirmed Bug #16159 in KSP 1.3.1 and it's not clear when and how it would be fixed. Not everyone is affected by this, but if you do, this mod can save your base from wrecking. The reason for bouncing is that sometimes the game places the vessel slightly beneath the ground and then turns on physics engine. The ground suddenly realizes that something got dented into it and kicks that thing out.
The mod prevents this by moving the vessel slightly above the ground just before the physics kicks in.

You can find more information about features and configuration in KSP Forum post.

** BACKUP YOUR GAME SAVE BEFORE TRYING THIS **

NOTE: This mod includes version checking using MiniAVC. If you opt-in, it will use the internet to check whether there is a new version available. Data is only read from the internet and no personal information is sent. For a more comprehensive version checking experience, please download the KSP-AVC Plugin.

WorldStabilizer