VBA Loop, Find & Copy run-time error '91': Object variable or With block variable not set

Hello

I'm getting an error message run-time error '91': Object variable or With block variable not set

PHP Code: 

Dim sStart As String
    Dim lTargetRow As Long
    Dim wsSource As Worksheet
    Dim wsTarget As Worksheet
    Dim rSourceCell As Range
    Dim LastRow As Long
    Dim searchRange As Range
     
    
     'Setup
    Application.ScreenUpdating = False
    
    
    Set wsTarget = Sheets("Sub-Analysis OUTPUT Desc")
    Set wsSource = Sheets("Sub-Analysis Core")
    
    Do While Not IsEmpty(rSourceCell)
    
   With wsSource
        LastRow = Range("B65536").End(xlUp).Row
   End With
    
    Set searchRange = Sheets("Sub-Analysis Core").Range("B5:B" & LastRow)
             'Get last used row in Target Sheet
        With wsTarget
            lTargetRow = .Range("B65536").End(xlUp).Offset(1, 0).Row
        End With
    
         'Get item being searched
         
        searchRange.Find(What:=Subname, After:=Range("B5"), LookIn:=xlValues, LookAt:= _
        xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNextRow, MatchCase:= _
        False).Activate
            
         'Save start address for comparison
        sStart = ActiveCell.Address
        Do
    'copy find result to target sheet
            ActiveCell.Copy Destination:=wsTarget.Cells(lTargetRow, 3)
            ActiveCell.Offset(0, -1).Copy Destination:=wsTarget.Cells(lTargetRow, 2)
            ActiveCell.Offset(0, 2).Copy Destination:=wsTarget.Cells(lTargetRow, 5)
            ActiveCell.Offset(0, 3).Copy Destination:=wsTarget.Cells(lTargetRow, 10)
   
          'Set destination = plus one Row
            lTargetRow = lTargetRow + 1

             'Find next item (til done)
            Cells.FindNext(After:=ActiveCell).Activate
        Loop Until ActiveCell.Address = sStart
        Set rSourceCell = rSourceCell.Offset(1, 0)    <<<<<< ERROR HERE  
Loop 


Basically I'm searching for specific text (Subname), picked up via user input thorugh InputBox, in a single column (column B in wsSource), copying that to wsTarget then going back to pick up other data in other columns on the same row, copying that data to wsTarget as well. Then loop to find next instance of Subname and repeat the copying priocess.
I'm experiencing a problem whereby the Find function is searching the whole sheet and not just column B.

Help on the problem(s) as ever much appreciated.

Thanks

Comment mark was lost in pasting to this thread. Already commented in original.

ok sorted the error message, I hadn't set the rSourceCell. Should have inserted

PHP Code: 

Set rSourceCell = Range("B5") 


after With wsource. Nevertheless I'm still experiencing the issue whereby the Find function searches the whole page but I only want to search Column B. Any ideas?
Thanks

ok I found the problem with restricting to one column. Have replaced the line (3rd from end):

PHP Code: 

Cells.FindNext(After:=ActiveCell).Activate 


with

HTML Code: 

thanks for your input