not sure why it happens on just 2 pc's

this is the code to count the times a jpg is opened....
Code:
        If lLogOnDate.ToString.Contains("/01/") Then
            My.Settings.jpg_01_Started = My.Settings.jpg_01_Started + 1
        End If
        If lLogOnDate.ToString.Contains("/02/") Then
            My.Settings.jpg_02_Started = My.Settings.jpg_02_Started + 1
        End If
        If lLogOnDate.ToString.Contains("/03/") Then
            My.Settings.jpg_03_Started = My.Settings.jpg_03_Started + 1
        End If
        If lLogOnDate.ToString.Contains("/04/") Then
            My.Settings.jpg_04_Started = My.Settings.jpg_04_Started + 1
        End If
        If lLogOnDate.ToString.Contains("/05/") Then
            My.Settings.jpg_05_Started = My.Settings.jpg_05_Started + 1
        End If
        If lLogOnDate.ToString.Contains("/06/") Then
            My.Settings.jpg_06_Started = My.Settings.jpg_06_Started + 1
        End If
and this is were the error occurred when adding to a list, writing to a txt file then uploading to a ftp

Name:  code.jpg
Views: 193
Size:  47.5 KB

a try catch fixed it...