Lack of harmony at the club

For a few seasons now ive been getting these messsages repeatedly, but I have no idea whats going wrong or how to fix it. Any clues?

check your players personal sheet, they may dislike some players or dont like the way the club is progressing, good idea is to sell the sour apples

It can be caused by many reasons. On top of what Stampler suggested, it can be also caused by bad form, players unhappy of not having enough games, or many unsettled players at the club (eg.: homesick).

Also, recently I found another reason: after a slump in form, I reacted angrily after a poor lost game (I was angry with the players as full game interaction); this normally make the players perform better in the following game (which they promptly did, beating the top of the league 3-1 at home).

Instead of praise them for the good performance, I foolishly told them "why don't you always play like that!" (I was still angry at the previous slump of result that was costing us the promotion spot). After that, the team moral went poor, and most of my players status were "concerned that I don't give too much faith to the players" .

I'm definitely not going to do that again

praise players who are playing well

sell people cause friction or send them on loan

offer them new contracts and it some times fixes any concerns

ask them to recomend players or staff and player may react positivly