Symptoms in BOD Manager:

When in OPS 32 and clicking on BOD manager then Sample setup, you get an error 94 invalid use of null, this error usually means there is a null record in a datatable somewhere in the database. 

Solution:

Make a back up of the database then open the database in Access and check the BOD tables first to see if there is anything out of the ordinary, i.e. the lack of a record associated with a variable or var ID.  Next check the vardesc table for a variable that exists but has no values associated with it, including blank fields, like description and shortname.  If there is no values associated with these records they should be deleted.  Exit and save your changes.

Symptoms in Spread Reports:

When in OPS 32 and you open a Report, you get one or more Error 94 messages.

Cause:

Most likely there are functions using the Optional Print Value functionality from Variable Setup.  If you create test conditions for an Optional Print Value (">", "<", ">=", "<=", or "=") and set a Value to compare, you MUST give it a text value to print.  If you do not specify a text value (leave the "What to Print if Threshold is crossed" field empty in Variable Setup, Optional Print Tab) you will recieve this error when the conditions are true.  This is because it is trying to print the text value from the "What to Print if Threshold is crossed" field and there is no value (NULL).  Hence, the Invalid Use of Null Error.

Solution:

The simple solution is to put a text value in the optional print tab's "What to Print..." field.  If you desire a blank to be printed, then put a <space> " " in the field.  A space is still a text value, whereas an empty field is NULL.