Getting conversion error, for value that doesnt exist in database
I was able to solve the problem by thinking about the error message for a minute. The error message says something about not being able to convert from varchar to int. So I looked for columns that should store a number, but were actually saving it as a varchar. The necessity of a cast was an indicator. 

So, I looked through each column in the EmployeeAttendance table, and found the offending record. 

Empname A B was stored in a column which should have either 1 or 0 values. This column is not a BIT, but a varchar(50) 

dies in shame

This table was a hand-me-down, and I think I need to get my janitors uniform out.