Eliminating and error in list and replacing it with above and below average

I have a list of values that is riddled with errors (#N/A). when I have formula's that reference values in the list it messes up my results. I want to eliminate the error and replace it with the average between the above and below value which i did figure out how to do. i.e. =IFERROR(Data!O12,(Data!O11+Data!O13)/2) .... "Data" is another worksheet that I am referencing. Where the problem lies when there is more than one error in a row. The formula finds the error but when there are two errors in a row, (Data!O11+Data!O13)/2) is using a cell with an error in to to add, and it just returns another error. I have been using many different logic statements, mainly nested IF AND functions but I am running into the same problem. i.e.

=IF((IFERROR(Data!AD362,FALSE))<>FALSE,Data!AD362,IF(AND(IFERROR(Data!AD361,TRUE)=TRUE,IFERROR(Data!AD363,TRUE)=TRUE),0,(Data!AD361+Data!AD363)/2))

or


=IF((IFERROR(AD362,FALSE)=AD362),AD362,(IF((IFERROR(AD361,FALSE)=AD361),(IF(IFERROR(AD363,FALSE)=AD363,(AD361+AD363)/2,0)),0)))


Let me know if anyone can figure this out, i'm sure its easy using a macro. I've attached the file.
Forum Sep Wheat example.xlsx

First off, thank you for the response. Second off, its close, but not exactly what i'm looking for.........

This is more what i'm looking for:

If Data!AD362 has an error, and the cell above and below both have a value in it, then :, (Data!AD361+Data!363)/2. If Data!AD362 doesn't have an error, 0 not 0, but the origional value in the cell.

So there are three different scenarios:
1.) if no error keep its value
2.) if there is an error and the above and below cell have a value, average them
3.) if there is an error and either the cell above or below also has an error, set equal to zero

I think the formula you had is almost correct, just need to alter it alittle

Does that make sense?