All rows produced in a union, intersect or minus of SELECT statements must have the same format, so the corresponding columns for each UNION, INTERSECT or MINUS statement must have the same data type or compatible data types. Two data types are compatible if you can convert one of them into the other; for example, INT and FLOAT are compatible data types because you can convert INT values to FLOAT values. In the current statement, a column in the second or subsequent SELECT statement does not agree with the corresponding column in a preceding SELECT statement.
Review and compare all the SELECT statements. Check each point at which one statement selects a column that is not identical to a column in the preceding SELECT statement. If the column data types do not match, then one type must be convertible to the other type.