Have to run macro twice, in order for it to work?

Hello, everyone! Having some trouble with a macro I've been working on. It's used to delete blanks (over a million blank rows) when another separate macro is run. If I get this one working, I would like to merge the two macros together.

First time it is clicked, it loads and acts like it's going to work. Less than a minute after loading...nothing happens (at least, visually). I click it again and it runs quickly; this time, it works.

Here is my very simple code:

Sub deleteBlankRows()
On Error Resume Next
ActiveSheet.Columns("A").SpecialCells(xlCellTypeBlanks).EntireRow.Delete
End Sub