I am trying to combine two different IFERROR statements with one if statement and am getting a #VALUE! error. Each of the three statements work fine by themselves, but I am having difficulty combining them into one.

The three individual statements are:
1. =IF(I2="MN-5536",30966,"")
2. =IFERROR(IF(VLOOKUP(I4,'Sheet2'!L:L,1,FALSE)=I4,""),"ENTER SUPPLIER #")
3. =IFERROR(IF(VLOOKUP(I10,'Sheet2'!$E$2:$G$65,1,FALSE)=I10,IF(S10<>"","enter supplier #")),"")

I have combined them into the below, but get a #VALUE! error.
=IF(I2="MN-5536",30966,IF(IFERROR(IF(VLOOKUP(I2,'Sheet2'!$E$2:$G$65,1,FALSE)=I2,IF(S2<>"","enter supplier #")),""),IF(IFERROR(IF(VLOOKUP(I2,'Sheet2'!L:L,1,FALSE)=I2,""),"ENTER SUPPLIER #"),"")))

Not sure if you would need to know the detail behind each function since they work fine individually. Let me know and I'll provide more detail if needed.