Psd error unsuccessful seeding

I’m getting this error at t=0.4

Error: There exists a NORMAL particle in a GHOST cell.
Particle may have gone OUT-OF-BOUNDS.
To resolve this issue, please consider:
 a) Verify all wall boundary conditions are defined
 b) Reducing the value of the variable NEIGHBOR_SEARCH_N (Solids>DEM>Max steps between neighbor search)
 c) Increasing the particle and/or wall stiffness (Solids>DEM>Normal spring constant or Young's modulus)
Current particle location (x, y, z coordinates): 0.6206E-01,  0.5063    ,  0.2131E-01
Current particle velocity (u, v, w components) : -1.109    ,  0.1710E-01,   102.5

Did you follow the suggestions in the error message?