Access 2016 Table Calculated Field - ms-access

Question

I have a table containing the following: Five Y/N fields and a calculated field [Priority Results] that totals the number of 'Yeses' from those five y/n fields. I'm trying to create another calculated field that will return a value of Low, Medium or High dependent on the number of boxes that have been checked. [Priority Results] currently returns the values 0 through -5. Low = 0 & -1, Medium = -2, High = -3 or lower. I've tried SEVERAL different versions of If/Then, If/Else, Iif statements and always receive a syntax error. I've read a lot of different sites and the following expression seems to be the most commonly used, but I'm still getting the error. Anyone have any ideas? I've even tried this statement on a non-calculated field and can't get it to work.
IIf([Priority results]<="-1","Low",IIf([Priority results]="-2","Medium",IIf([Priority results]>="-3","High")))
Here are the calculated field [Priority results] properties.
Expression:
[Class Non-Attendance]+[Instructor Referral]+[Late Registration]+[Low Starting GPA]+[Talon Log-in]
Result Type: Long Integer
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The part of the table this question relates to has the following fields:
Class Non-Attendance: Yes/No
Instructor Referral: Yes/No
Late Registration: Yes/No
Low Starting GPA: Yes/No
Talon Log-In: Yes/No
Priority Results: Calculated field counting the Yes/No fields above
Priority Outcome: Calculated field (that isn't working) prioritizing based on Priority Results

Answer 1

Don't put parameters for number fields in quotes.
Consider:
IIf(Abs([Priority Results])<=1, "Low", IIf(Abs([Priority Results])=2, "Medium", "High"))
In a query or textbox, expression could be:
Switch(Abs([Priority Results])<=1, "Low", Abs([Priority Results])=2, "Medium", True, "High")

Answer 2

Parts of the question still confuse me, which is why this answer will be brief. You have a calculated field PriorityOutcome based on another calculated field PriorityResults and that is the problem. Access doesn't calculate PriorityResults before calculating PriorityOutcome. Instead Access says PriorityResults doesn't exist yet and passes null to PriorityOutcome resulting in either an error or a silent fail.
There are several fixes you can mix and match. You can repeat the calculation for PriorityResults inside PriorityOutcome: wasteful but often the fastest solution. You can also add a code module with public functions to do part or all of the calculations. Then refer to those public functions in your calculated fields Access intellisense can find public functions.