The type of one of the expressions in the join clause is incorrect in Entity Framework

The types and the names of the properties in the anonymous types must match:

new { p1 = q.QOT_SEC_ID, p2 = dpr.DPR_TS } 
    equals 
new { p1 = (decimal)p.PAY_SEC_ID, p2 = p.PAY_DATE }

or if p.PAY_SEC_ID were an int?:

new { p1 = (int?)q.QOT_SEC_ID, p2 = dpr.DPR_TS } 
    equals 
new { p1 = p.PAY_SEC_ID, p2 = p.PAY_DATE }

…which will find no matches if PAY_SEC_ID is null, or

new { p1 = q.QOT_SEC_ID, p2 = dpr.DPR_TS } 
    equals 
new { p1 = p.PAY_SEC_ID.GetValueOrDefault(), p2 = p.PAY_DATE }

…which defaults p1 to 0 when PAY_SEC_ID is null and again no match will be found (assuming that ID values will never be 0).