diff --git a/ucs-school-umc-printermoderation/umc/python/printermoderation/__init__.py b/ucs-school-umc-printermoderation/umc/python/printermoderation/__init__.py
index e3b62bd..78d9898 100644
--- a/ucs-school-umc-printermoderation/umc/python/printermoderation/__init__.py
+++ b/ucs-school-umc-printermoderation/umc/python/printermoderation/__init__.py
@@ -39,7 +39,7 @@ import subprocess
 
 from univention.lib.i18n import Translation
 
-from univention.management.console.modules import UMC_OptionTypeError, UMC_Error
+from univention.management.console.modules import UMC_Error
 from univention.management.console.modules.decorators import simple_response, sanitize
 from univention.management.console.modules.sanitizers import StringSanitizer
 from univention.management.console.log import MODULE
@@ -85,7 +85,7 @@ class Instance(SchoolBaseModule):
 		username = username.replace('/', '')
 		path = os.path.join(CUPSPDF_DIR, username, CUPSPDF_USERSUBDIR, printjob)
 		if not os.path.realpath(path).startswith(os.path.realpath(CUPSPDF_DIR)):
-			raise UMC_OptionTypeError('Invalid file')
+			raise UMC_Error('Invalid file')
 		return path
 
 	def _get_all_username_variants(self, username):
@@ -164,7 +164,7 @@ class Instance(SchoolBaseModule):
 		path = self._get_path(request.options['username'], request.options['printjob'])
 
 		if not os.path.exists(path):
-			raise UMC_OptionTypeError('Invalid file')
+			raise UMC_Error('Invalid file')
 
 		with open(path) as fd:
 			self.finished(request.id, fd.read(), mimetype='application/pdf')
@@ -217,13 +217,13 @@ class Instance(SchoolBaseModule):
 		try:
 			spoolhost, printer = printer.split('://', 1)
 		except ValueError:
-			raise UMC_OptionTypeError('Invalid printer URI')
+			raise UMC_Error('Invalid printer URI')
 
 		if spoolhost == self.fqdn:
 			spoolhost = None
 
 		if not os.path.exists(path):
-		        raise UMC_Error('File %s doesnt exists' % path)
+			raise UMC_Error(_('File %r could not be printed as it does not exists (anymore).') % (printjob,))
 		
 		MODULE.info('Deleting print job %r' % (path,))
 		cmd = [
@@ -240,7 +240,7 @@ class Instance(SchoolBaseModule):
 			path,
 		]
 		if spoolhost:
-		        cmd.extend([
+			cmd.extend([
 				# spool host
 				'-H', spoolhost
 			])
@@ -249,7 +249,7 @@ class Instance(SchoolBaseModule):
 		lpr = subprocess.Popen(cmd, shell=False, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
 		(stdout, stderr) = lpr.communicate()
 		if lpr.returncode != 0:
-			raise UMC_Error(_('Failed to print on %s: %s' % (printer, stderr)))
+			raise UMC_Error(_('Failed to print on %s: %s') % (printer, stderr))
 
 		return True