VB.NET Constantly polling a directory for files is causing an ongoing increase in memory usage - vb.net

Question

I have a small application that on startup instantiates a class, reads in a JSON array from a text file and builds an object. It then initialises a new system.timers.timer and scans a directory every xx minute(s) to get a file count.
When my application starts up, Windows Task Manager shows it at around 13MB of Memory, however, leaving it to run for about 12 hours now shows it at 700+MB of Memory when no files were even detected in this directory. I'm worried that this is just going to grow forever and eventually crash. It doesn't seem like anything is getting cleaned up by the GC (probably because my timer and objects are always active).
Although this class is quite simple in theory, I do have other functions and timers involved that don't get called until required. I am happy to post all my code somewhere, or even just the class, but it's a little too long to add to this post.
I have included the main elements of my class however:
Public Sub Initialize()
Try
If AgentSettings.DebugMode Then CreateLog("Entered Module: Initialize()")
CreateLog("Initializing Alerting Rule: <" & Me.Name & ">")
CreateLog("Validating all Rule Profiles")
'Loop through all the Rule Profiles and make sure they are all valid
'If not, disable the profile so it never scans
For Each profile As RuleProfile In Me.RuleProfiles
CreateLog("Verifying Profile: <" & profile.Name & ">")
'Check to make sure the Profile is functionally valid
If ProfileIsValid(profile) Then
'Profile is valid so setup an event handler to handle the isBroken event
profile.Active = True
CreateLog("Rule Profile: <" & profile.Name & "> Enabled")
AddHandler profile.BrokenStatusChanged, AddressOf CheckIfRuleIsBroken
Else
'Disable the Profile
CreateLog("Rule Profile: <" & profile.Name & "> Disabled")
profile.Active = False
End If
Next
'Setup the checking timer and set the interval to the default checking time
If Me.ruleCheckTimer Is Nothing Then
Me.ruleCheckTimer = New System.Timers.Timer
Me.ruleCheckTimer.AutoReset = True
Me.ruleCheckTimer.Interval = Me.DefaultMinutesToCheck * 60000
AddHandler Me.ruleCheckTimer.Elapsed, AddressOf CheckRule
End If
'If there is an escalation plan then setup a timer for it
If Me.EscalationPlan.PlanItems.Count > 0 Then
'Setup the escalation timer and set the interval to the first plan item
If Me.escalationTimer Is Nothing Then
Me.escalationTimer = New System.Timers.Timer
Me.escalationTimer.AutoReset = True
AddHandler Me.escalationTimer.Elapsed, AddressOf Escalate
End If
End If
Catch ex As Exception
CreateLog("Module: Initialize()" & vbNewLine & "Exception Error: " & ex.Message)
End Try
End Sub
Private Sub CheckRule(ByVal sender As Object, ByVal e As EventArgs)
Try
If AgentSettings.DebugMode Then CreateLog("Entered Module: CheckRule()")
'Loop through all the profiles
For Each profile As RuleProfile In Me.RuleProfiles
CreateLog("Scanning for active profiles")
'Make sure the Profile is active
If profile.Active Then
Select Case profile.Name
Case "FileCount"
CreateLog("Checking Rule Profile: <" & profile.Name & "> for isBroken status")
'Get file count of the specified directory
Dim files As String()
files = Directory.GetFiles(profile.DirectoryPath)
'Determine if we're checking for files greater than or less than
If profile.GreaterThan Then
If files.Count > profile.FileCount Then
profile.isBroken = True
Else
profile.isBroken = False
End If
Else
If files.Count < profile.FileCount Then
profile.isBroken = True
Else
profile.isBroken = False
End If
End If
files = Nothing
End Select
End If
Next
Catch ex As Exception
CreateLog("Module: CheckRule()" & vbNewLine & "Exception Error: " & ex.Message)
End Try
End Sub
When profile.isBroken receives an update, it triggers an event which then loops through all profiles to determine which ones are broken. If all are broken, then it begins its alerting and escalation process. However, none of this is occurring and my memory is still increasing constantly.
Can anyone see anything wrong with this? Or maybe a better way (and more efficient way) of polling this directory?
The theory behind my application is to instantiate multiple classes to allow various directories or files to be scanned, but if the memory has increased this much with just the one instance, I'm concerned about running multiple.
EDITED
My log handling is as follows:
Public Sub CreateLog(ByVal text As String)
Try
'Create Log Directory if it doesn't exist
If (Not System.IO.Directory.Exists(GetFolderPath(SpecialFolder.CommonApplicationData) & "\MyCompany\Agent\Log")) Then System.IO.Directory.CreateDirectory(GetFolderPath(SpecialFolder.CommonApplicationData) & "\MyCompany\Agent\Log\")
'Write log entry
LogFile = GetFolderPath(Environment.SpecialFolder.CommonApplicationData) & "\MyCompany\Agent\Log\" & "Logfile - " & Format(Now, "ddMMyyyy") & ".txt"
File.AppendAllText(LogFile, DateTime.Now.ToString("dd/MM/yyyy HH:mm:ss") & " " & text & Environment.NewLine)
'Update the activity text on the main UI
frmMain.UpdateActivityText(text)
Catch ex As Exception
'No need to create a log entry
End Try
End Sub