diff --git a/comictaggerlib/cli.py b/comictaggerlib/cli.py
index 91e10fc..25acae1 100644
--- a/comictaggerlib/cli.py
+++ b/comictaggerlib/cli.py
@@ -509,7 +509,14 @@ def process_file_cli(filename, opts, settings, match_results):
         renamer.setSmartCleanup(settings.rename_use_smart_string_cleanup)
         renamer.move = settings.rename_move_dir
 
-        new_name = renamer.determineName(filename, ext=new_ext)
+        try:
+            new_name = renamer.determineName(filename, ext=new_ext)
+        except Exception as e:
+            print(msg_hdr + "Invalid format string!\nYour rename template is invalid!\n\n"
+                "{}\n\nPlease consult the template help in the settings "
+                "and the documentation on the format at "
+                "https://docs.python.org/3/library/string.html#format-string-syntax", file=sys.stderr)
+            return
 
         folder = os.path.dirname(os.path.abspath(filename))
         if settings.rename_move_dir and len(settings.rename_dir.strip()) > 3:
diff --git a/comictaggerlib/filerenamer.py b/comictaggerlib/filerenamer.py
index 150c01b..0b9f2ba 100644
--- a/comictaggerlib/filerenamer.py
+++ b/comictaggerlib/filerenamer.py
@@ -16,7 +16,6 @@
 
 import os
 import re
-import datetime
 import sys
 import string
 
diff --git a/comictaggerlib/renamewindow.py b/comictaggerlib/renamewindow.py
index abe856d..6ff51c1 100644
--- a/comictaggerlib/renamewindow.py
+++ b/comictaggerlib/renamewindow.py
@@ -77,7 +77,19 @@ class RenameWindow(QtWidgets.QDialog):
                 md = ca.metadataFromFilename(self.settings.parse_scan_info)
             self.renamer.setMetadata(md)
             self.renamer.move = self.settings.rename_move_dir
-            new_name = self.renamer.determineName(ca.path, ext=new_ext)
+
+            try:
+                new_name = self.renamer.determineName(ca.path, ext=new_ext)
+            except Exception as e:
+                QtWidgets.QMessageBox.critical(self, 'Invalid format string!',
+                    'Your rename template is invalid!'
+                    '<br/><br/>{}<br/><br/>'
+                    'Please consult the template help in the '
+                    'settings and the documentation on the format at '
+                    '<a href=\'https://docs.python.org/3/library/string.html#format-string-syntax\'>'
+                    'https://docs.python.org/3/library/string.html#format-string-syntax</a>'.format(e))
+                return
+
 
             row = self.twList.rowCount()
             self.twList.insertRow(row)
diff --git a/comictaggerlib/settingswindow.py b/comictaggerlib/settingswindow.py
index 28978b9..03260d5 100644
--- a/comictaggerlib/settingswindow.py
+++ b/comictaggerlib/settingswindow.py
@@ -24,6 +24,8 @@ from .settings import ComicTaggerSettings
 from .comicvinecacher import ComicVineCacher
 from .comicvinetalker import ComicVineTalker
 from .imagefetcher import ImageFetcher
+from .filerenamer import FileRenamer
+from .genericmetadata import GenericMetadata
 from . import utils
 
 
@@ -154,6 +156,65 @@ class SettingsWindow(QtWidgets.QDialog):
         self.btnTestKey.clicked.connect(self.testAPIKey)
         self.btnTemplateHelp.clicked.connect(self.showTemplateHelp)
 
+    def configRenamer(self):
+        md = GenericMetadata()
+        md.isEmpty = False
+        md.tagOrigin = "testing"
+
+        md.series = "series name"
+        md.issue = "1"
+        md.title = "issue title"
+        md.publisher = "lordwelch"
+        md.month = 4
+        md.year = 1998
+        md.day = 4
+        md.issueCount = 1
+        md.volume = 256
+        md.genre = "test"
+        md.language = "en"  # 2 letter iso code
+        md.comments = "This is definitly not something you want to read."  # use same way as Summary in CIX
+
+        md.volumeCount = 4096
+        md.criticalRating = "Worst Comic Ever"
+        md.country = "US"
+
+        md.alternateSeries = "None"
+        md.alternateNumber = 4.4
+        md.alternateCount = 4444
+        md.imprint = 'Welch Publishing'
+        md.notes = "This doesn't actually exist"
+        md.webLink = "https://example.com/series name/1"
+        md.format = "Box Set"
+        md.manga = "Yes"
+        md.blackAndWhite = False
+        md.pageCount = 4
+        md.maturityRating = "Everyone"
+
+        md.storyArc = "None of your buisness"
+        md.seriesGroup = "Advertures of buisness"
+        md.scanInfo = "(lordwelch)"
+
+        md.characters = "lordwelch, Welch"
+        md.teams = "None"
+        md.locations = "Earth, 444 B.C."
+
+        md.credits = [dict({'role': 'Everything', 'person': 'lordwelch', 'primary': True})]
+        md.tags = ["testing", "not testing", "fake"]
+        md.pages = [dict({'Image': '0', 'Type': 'Front Cover'}), dict({'Image': '1', 'Type': 'Story'})]
+
+        # Some CoMet-only items
+        md.price = 0.00
+        md.isVersionOf = "SERIES #1"
+        md.rights = "None"
+        md.identifier = "LW4444-Comic"
+        md.lastMark = "0"
+        md.coverImage = "https://example.com/series name/1/cover"
+
+        self.renamer = FileRenamer(md)
+        self.renamer.setTemplate(str(self.leRenameTemplate.text()))
+        self.renamer.setIssueZeroPadding(self.settings.rename_issue_number_padding)
+        self.renamer.setSmartCleanup(self.settings.rename_use_smart_string_cleanup)
+
     def settingsToForm(self):
 
         # Copy values from settings to form
@@ -212,6 +273,21 @@ class SettingsWindow(QtWidgets.QDialog):
 
     def accept(self):
 
+        self.configRenamer()
+
+
+        try:
+            new_name = self.renamer.determineName('test.cbz')
+        except Exception as e:
+            QtWidgets.QMessageBox.critical(self, 'Invalid format string!',
+                'Your rename template is invalid!'
+                '<br/><br/>{}<br/><br/>'
+                'Please consult the template help in the '
+                'settings and the documentation on the format at '
+                '<a href=\'https://docs.python.org/3/library/string.html#format-string-syntax\'>'
+                'https://docs.python.org/3/library/string.html#format-string-syntax</a>'.format(e))
+            return
+
         # Copy values from form to settings and save
         self.settings.rar_exe_path = str(self.leRarExePath.text())
 
@@ -333,7 +409,8 @@ class SettingsWindow(QtWidgets.QDialog):
 
     def showTemplateHelp(self):
         TemplateHelpWin = TemplateHelpWindow(self)
-        TemplateHelpWin.exec_()
+        TemplateHelpWin.setModal(False)
+        TemplateHelpWin.show()
 
 class TemplateHelpWindow(QtWidgets.QDialog):
 
diff --git a/comictaggerlib/ui/TemplateHelp.ui b/comictaggerlib/ui/TemplateHelp.ui
index 4540fc1..cba4db9 100644
--- a/comictaggerlib/ui/TemplateHelp.ui
+++ b/comictaggerlib/ui/TemplateHelp.ui
@@ -55,7 +55,7 @@
 {criticalRating}&#009;(string)
 {country}&#009;(string)
 {alternateSeries}&#009;(string)
-{alternateinteger}&#009;(string)
+{alternateNumber}&#009;(string)
 {alternateCount}&#009;(integer)
 {imprint}&#009;&#009;(string)
 {notes}&#009;&#009;(string)
@@ -76,8 +76,8 @@
 {pages}&#009;&#009;(list of dict({&apos;Image&apos;: &apos;str(int)&apos;, &apos;Type&apos;: &apos;str&apos;}))
 
 CoMet-only items:
-{price}&#009;&#009;(integer)
-{isVersionOf}&#009;(boolean)
+{price}&#009;&#009;(float)
+{isVersionOf}&#009;(string)
 {rights}&#009;&#009;(string)
 {identifier}&#009;(string)
 {lastMark}&#009;(string)
diff --git a/comictaggerlib/ui/settingswindow.ui b/comictaggerlib/ui/settingswindow.ui
index 9b97e76..2ca8f89 100644
--- a/comictaggerlib/ui/settingswindow.ui
+++ b/comictaggerlib/ui/settingswindow.ui
@@ -520,28 +520,27 @@ Accepts the following variables:
 {issue}		(string)
 {title}		(string)
 {publisher}	(string)
-{month}		(number)
-{year}		(number)
-{day}		(number)
-{date}		(Date)
-{issueCount}	(number)
-{volume}	(number)
+{month}		(integer)
+{year}		(integer)
+{day}		(integer)
+{issueCount}	(integer)
+{volume}	(integer)
 {genre}		(string)
 {language}	(string)
 {comments}	(string)
-{volumeCount}	(number)
+{volumeCount}	(integer)
 {criticalRating}	(string)
 {country}	(string)
 {alternateSeries}	(string)
 {alternateNumber}	(string)
-{alternateCount}	(number)
+{alternateCount}	(integer)
 {imprint}		(string)
 {notes}		(string)
 {webLink}	(string)
 {format}		(string)
 {manga}		(string)
 {blackAndWhite}	(boolean)
-{pageCount}	(number)
+{pageCount}	(integer)
 {maturityRating}	(string)
 {storyArc}	(string)
 {seriesGroup}	(string)
@@ -554,8 +553,8 @@ Accepts the following variables:
 {pages}		(list of dict({'Image': 'str(int)', 'Type': 'str'}))
 
 CoMet-only items:
-{price}		(number)
-{isVersionOf}	(boolean)
+{price}		(float)
+{isVersionOf}	(string)
 {rights}		(string)
 {identifier}	(string)
 {lastMark}	(string)