crystal reports 13 close IIS ApplicationPool

Everything was fine in ws2008, CRforVS_13_0_5, vs2008 but recently i updated the application to ws2012, CRforVS_13_0_15, vs2015, the application is ok but when i print reports "sometimes" the IIS ApplicationPool  is closed, i have to recycle when this happen.

In the event viewer the error is can't load report especif in this line

crystalReport.Load(Server.MapPath("reportes/acciones.rpt"));