In the beginning of the code I'm adding a unique number to the subject. for example the subject of the email was: "Welcome to excelforum" and the code changes it to : "Welcome to excelforum #memberid 2321".

At the code where the first error originates:
         objItem = Mid(objItem, InStr(objItem, "#") + 1)
I'm looking if this email already received a unique number. If it has the subject of the e-mail has an "#" sign.

If it doesnt have the "#" sign the position of the sign would be 0 and a new unique number is added. If it has a unique sign the number won't be added again.

If InStr(objItem, "#") > 0 Then
             strTicket = "PromiseIII_" & Left(objItem, InStr(objItem, "#") - 1)
         End If