Just in case you come across a phenomenon your UserForm hangs Excel, you might want to runt the below code to eliminate all Alt+Enter entries on your sheet [that is Chr(10)], what is a new row initiation within a cell.
Cause that is what hangs Excel when a control of a UserForm wants to pick the equivalent character from the cell. 

Sub RemoveALTentr()
'Range("A2").Select
    Cells.Replace What:=Chr(10), Replacement:=" ", LookAt:=xlPart, SearchOrder _
        :=xlByRows, MatchCase:=False, SearchFormat:=False, ReplaceFormat:= _
        False
End Sub
Stay tuned
Cheers, Gabor