VBA/Excel - cells not recognised as blank until I select and press enter - vba

Question

I have a macro which generates an output sheet to drop into a purpose-built (in C#) application for processing sheets of this type.
Essentially, the code copies one of the sheets from the master sheet and then saves it using a user-generated reference. It then copies and pastes all of the cells in the sheet as values.
Very frustratingly, in two of the columns in the output sheets, the cells with numbers in them are interspersed with supposedly non-blank cells which do not contain any characters or spaces (and are formatted as "general"). When I use an "IsBlank" formula, these return "FALSE". However, if I manually click on the cells in question and press "enter", these suddenly return a "TRUE" value.
I am considering getting the macro to select every cell in these columns one by one to resolve this, but that seems criminally inefficient.
Is there a better solution to this problem?

Answer 1

If ISBLANK formula is returning "FALSE", but hitting F2 + Enter return the same as "TRUE", then check if formulas => Workbook calculation is set as "Manual".
Also, data copied from external source may contain non-breaking space, with which Excel often struggles.
If clicking the cell is the only thing that works, you may add a small piece of code block like this, which'll refresh the selected range:
Sub refresh()
Dim r1 As Range, r2 As Range
Set r2 = Selection
For Each r1 In r2
r1.Select
Application.SendKeys "{f2}{enter}"
DoEvents
Next
End Sub

Answer 2

What you might be experiencing are zero length strings.It may have been the result of a formula which evaluates to "" (e.g. ="") and then copied and pasted as values.
As I understand, you are using macro. If that is the case, you use AutoFilter method of Range Object to get all non-blank cells. Something like:
Dim r as Range
Set r = Sheet1.Range("Your Range") '/* from your master sheet */
'/* Filter all non-blanks */
'/* First argument 1 depends on the column you want filtered */
'/* For this example it is column 1 of your range */
r.AutoFilter 1, "<>"
r.SpecialCells(xlCellTypeVisible).Copy
Sheet2.Range("Your Destination").PasteSpecial xlPasteValues
Hope this helps.