The spreadsheet is a roster, Names for row headers and dates for column headers, it counts the number of like entries in a column and the validation stops further entries when a limit is reached.
The Validation is formula based that requires a referenced cell to be TRUE to allow the entry of that code
Referenced cell=TRUE
=E296=TRUE
The Referenced cell is an AND statement.
=AND(LEFT(E8,1)<>" ",RIGHT(E8,1)<>" ",COUNTIF(E$8:E$41,$B$156)<=E$214,COUNTIF(E$8:E$41,$B$157)<=E$215,COUNTIF(E$8:E$41,$B$158)<=E$216,COUNTIF(E$8:E$41,$B$159)<=E$217,COUNTIF(E$8:E$41,$B$160)<=E$218,COUNTIF(E$8:E$145,$B$166)<=E$224,COUNTIF(E$8:E$145,$B$167)<=E$225,COUNTIF(E$8:E$145,$B$168)<=E$226,COUNTIF(E$8:E$145,$B$169)<=E$227,COUNTIF(E$8:E$145,$B$170)<=E$228,OR(COUNTIF(ShiftCode,E8)=1,ISBLANK(E8)))
It does not fail at any particular time it is a random event, it does not fail at all if I reduce the active processors to one.
When you see a failure, if you re-calcuilate, without changing any data at all on the worksheet, i.e. after CTRL+SHIFT+ALT+F9 (hold down the first three keys and hit F9) what happens with multi-processors. If the result changes, that possibly might relate to threading or order of calculations, or dependencies. If the result remains the same, there may be a different problem.
I've not read of this kind of formula being dependent on the number of processors. before. With this complex code, I would advise checking it very closely for a logic issue. Here is what I would suggest.
1. Confirm that you have XP Service Pack 3 and that it is 32 bit and not 64 bit.
2. At the time it fails, verify (by highlighting the section of code and hitting <F9> that each segment is calculating properly individually (or place them in separate cells to do that).
Here is the code laid out so as to allow easier visualization:
=AND(LEFT(E8,1)<>" ",RIGHT(E8,1)<>" ",
COUNTIF(E$8:E$41,$B$156)<=E$214,
COUNTIF(E$8:E$41,$B$157)<=E$215,
COUNTIF(E$8:E$41,$B$158)<=E$216,
COUNTIF(E$8:E$41,$B$159)<=E$217,
COUNTIF(E$8:E$41,$B$160)<=E$218,
COUNTIF(E$8:E$145,$B$166)<=E$224,
COUNTIF(E$8:E$145,$B$167)<=E$225,
COUNTIF(E$8:E$145,$B$168)<=E$226,
COUNTIF(E$8:E$145,$B$169)<=E$227,
COUNTIF(E$8:E$145,$B$170)<=E$228,
OR(COUNTIF(ShiftCode,E8)=1,ISBLANK(E8)))
To "highlight a section", in the formula bar, you take the cursor, place it on (for example), the C in COUNTIF; left click and drag across to the 4 in E$214 (but not the comma). Then <F9> should show the result of calculating just that segment.
If the above does not bring a solution, I would suggest posting a (sanitized as necessary) copy of the workbook (that shows the problem) to some publically accessible site (e.g. SkyDrive) and posting a link here in the hope that someone with XP SP3 and Excel 2010 can see if they can reproduce (and hopefully diagnose) your problem.
