Excel validation lists avoid blanks and errors with TOCOL(ignore) plus FILTER; the spill range stays stable across worksheets.
If Excel freezes when deleting rows or columns, identify the possible causes and then resolve the issue. Turn off Auto Save, disable COM Add-ins, etc.
Stop hunting through tabs—build a portable custom ribbon containing your favorite commands and Excel's most useful secret tools.
Use dynamic arrays and tables for fast, scalable cascading drop-down lists in modern Excel.