Water softner

Does anyone know why my water softner turned to fluid 2 days after checking the salt level and it was just fine at the level of the salt I poured into the softner. And why did it fill half way up with water melting the salt. Is this a common problem and fixable?

Looking for some advice as to how to fix water softener problem filled it with the salt and 2 days later when I checked it there was all water in tank.