Try this instead..

automatic/tinymediamanager/update.ps1

@@ -1,7 +1,7 @@
 Import-Module au
 Import-Module "$PSScriptRoot\..\..\scripts\au_extensions.psm1"
 
-$releasev3 = 'https://release.tinymediamanager.org/download_v3.html'
+#$releasev3 = 'https://release.tinymediamanager.org/download_v3.html'
 $releasev4 = 'https://release.tinymediamanager.org/download_v4.html'
 $releasev5 = 'https://release.tinymediamanager.org/download_v5.html'
 
@@ -74,29 +74,29 @@ function GetV4Version() {
   }
 }
 
-function GetV3Version() {
-  $download_page = Invoke-WebRequest -Uri $releasev3 -UseBasicParsing
-
-  #tmm_3.1.17_win.zip
-  $re = "tmm_3.+_*_win.zip$"
-  $url = $download_page.links | Where-Object href -Match $re | Select-Object -Last 1 -expand href
-
-  $version = $url -split 'tmm_|_.*?.zip' | Select-Object -Last 1 -Skip 1
-  $url32 = 'https://release.tinymediamanager.org/' + $url
-
-  @{
-    Version = $version
-    URL32   = $url32
-  }
-}
+#function GetV3Version() {
+#  $download_page = Invoke-WebRequest -Uri $release -UseBasicParsing
+#
+#  #Version v3.1.18
+#  $versionRegEx = 'Version\s+v3.+'
+#  $version = ([regex]::match($download_page.Content, $versionRegEx) -replace ("Version v", ""))
+#
+#  #https://archive.tinymediamanager.org/v3.1.18/tmm_3.1.18_win.zip
+#  $url32 = "https://archive.tinymediamanager.org/v$version/tmm_$version" + "_win.zip"
+#
+#  @{
+#    Version = $version
+#    URL32   = $url32
+#  }
+#}
 
 function global:au_GetLatest {
-  $v3Stream = GetV3Version
+#  $v3Stream = GetV3Version
   $v4Stream = GetV4Version
   $v5Stream = GetV5Version
 
   $streams = [ordered] @{
-    v3 = $v3Stream
+#    v3 = $v3Stream
     v4 = $v4Stream
     v5 = $v5Stream
   }