Get InvalidOperatorException was unhandled upon compiling - vb.net

Question

Everything was compiling just fine until validation for text fields was implemented.
Why won't it compile?
An error occurred creating the form.
See Exception.InnerException for
details. The error is: External
component has thrown an exception.
The source:
Public Class frmAddStudent
Dim aryData(6) As String
Public Shared newStudentRecord As String
Private Sub btnCancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCancel.Click
Me.DialogResult = DialogResult.Cancel
End Sub
Private Sub btnAddStudent_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAddStudent.Click
'place all the student field data into the array of elements
aryData(0) = txtFirstName.Text
aryData(1) = txtLastName.Text
aryData(2) = txtMajor.Text
aryData(3) = txtPhone.Text
aryData(4) = txtEmail.Text
aryData(5) = txtGPA.Text
'join the array elements and place the result into a string variable
newStudentRecord = Join(aryData, " ")
'create a link between the form and the file with streamwriter and write to the text file
If System.IO.File.Exists(frmMain.FILE_NAME) = True Then
Dim objWriter As New System.IO.StreamWriter(frmMain.FILE_NAME, True)
objWriter.WriteLine(newStudentRecord)
objWriter.Close()
End If
Me.DialogResult = DialogResult.OK
End Sub
Private Sub txtFirstName_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles txtFirstName.Validating
If txtFirstName.Text.Contains(" ") Or txtFirstName.Text.Length = 0 Or Not System.Text.RegularExpressions.Regex.IsMatch(txtFirstName.Text, "[a-z|A-Z]+$") Then
ErrorProvider1.SetError(txtFirstName, "First Name can't contain spaces or be of zero length and must consist of only letters")
e.Cancel = True
Else
ErrorProvider1.SetError(txtFirstName, "")
End If
End Sub
Private Sub frmAddStudent_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
ErrorProvider1.BlinkStyle = ErrorBlinkStyle.NeverBlink
End Sub
Private Sub txtLastName_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles txtLastName.Validating
If txtLastName.Text.Contains(" ") Or txtLastName.Text.Length = 0 Or Not System.Text.RegularExpressions.Regex.IsMatch(txtLastName.Text, "[a-z|A-Z]+$") Then
ErrorProvider1.SetError(txtLastName, "Last Name can't contain spaces or be of zero length and must consist of only letters")
e.Cancel = True
Else
ErrorProvider1.SetError(txtLastName, "")
End If
End Sub
Private Sub txtMajor_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles txtMajor.Validating
If txtMajor.Text.Length > 0 Then
If Not System.Text.RegularExpressions.Regex.IsMatch(Strings.Left(txtMajor.Text, 1), "[a-z|A-Z]+$") Then
ErrorProvider1.SetError(txtMajor, "Major course code is incorrect")
Else
ErrorProvider1.SetError(txtMajor, "")
End If
Else
ErrorProvider1.SetError(txtMajor, "Major cant' be zero length")
End If
End Sub
End Class
EDIT: Here's also a link to a PrtSc of the problem: http://img88.imageshack.us/i/imageqc.gif/