The three core challenges in KM

There are three main challenges in introducing KM. We can call them Awareness, Willingness, and Ability

The awareness challenge can be summed up as follows

The people who have the crucial knowledge, are often unaware that they have it, are unaware how valuable it is, are unaware who needs to know it, and would not know how to go about sharing it anyway.

The people who need the knowledge are often unaware that they lack it, unaware that they need it, unaware that it exists already, are unaware of who holds that knowledge, and would not know how to go about acquiring it anyway.

The willingness challenge can be summed up as follows

The people who have the crucial knowledge, are unwilling to share it. They fear that sharing knowledge will cost them time and effort, and may in some way disempower them.

The people who need the knowledge are unwilling to look for it.  They fear that admitting a need for knowledge makes them look incompetent, or they prefer the fun of creating the knowledge for themselves.

The ability challenge can be summed up as follows

The people who have the crucial knowledge, are unable to share it. They don't know who to share it with, where to put it, or how to share it.

The people who need the knowledge are unable to find it.  They don't know where to look,who to talk to, or how to search.

To address these challenges, you need to make the case for KM and raise the awareness, analyse and address the cultural aspects behind any unwillingness, and  introduce a framework which provides the ability to seek and share.