diff --git a/advlabdb/database_import.py b/advlabdb/database_import.py
index 959097e..31efcfc 100644
--- a/advlabdb/database_import.py
+++ b/advlabdb/database_import.py
@@ -6,7 +6,7 @@ from flask import flash
 from sqlalchemy import select
 
 from . import data_dir
-from .exceptions import DataBaseImportException
+from .exceptions import DatabaseImportException
 from .models import (
     Appointment,
     Assistant,
@@ -42,7 +42,7 @@ def nullable(entry):
 
 def not_nullable(entry):
     if is_null(entry):
-        raise DataBaseImportException("Unnullable entry is NULL!")
+        raise DatabaseImportException("Unnullable entry is NULL!")
 
     return entry.strip()
 
@@ -54,7 +54,7 @@ def importFromFile(filePath: Path):
     db_bk_dir.mkdir(exist_ok=True)
 
     if filePath.name[-4:] != ".txt":
-        raise DataBaseImportException(
+        raise DatabaseImportException(
             "The import file has to be a text file with txt extension (.txt at the end of the filename)!"
         )
 
@@ -82,7 +82,7 @@ def importFromFile(filePath: Path):
 
             if expectingTable:
                 if line[0] != "#":
-                    raise DataBaseImportException(f"Expected a Table name starting with # but got this line: {line}")
+                    raise DatabaseImportException(f"Expected a Table name starting with # but got this line: {line}")
 
                 expectingTable = False
                 tableName = line[1:]
@@ -104,7 +104,7 @@ def importFromFile(filePath: Path):
                 elif tableName == "Appointment":
                     activeDict = appointments
                 else:
-                    raise DataBaseImportException(f"{tableName} is not a valid table name!")
+                    raise DatabaseImportException(f"{tableName} is not a valid table name!")
 
                 readHeader = True
                 continue
@@ -122,7 +122,7 @@ def importFromFile(filePath: Path):
 
             cellsLen = len(cells)
             if cellsLen != len(activeDict["_header"]):
-                raise DataBaseImportException(
+                raise DatabaseImportException(
                     f"The number of header cells is not equal to the number of row cells in row {cells}!"
                 )
 
@@ -134,14 +134,14 @@ def importFromFile(filePath: Path):
         flash("Semester...")
 
         if len(semesters["label"]) != 1:
-            raise DataBaseImportException("Only one semester is allowed in an import file!")
+            raise DatabaseImportException("Only one semester is allowed in an import file!")
 
         semesterLabel = not_nullable(semesters["label"][0])
         semesterYear = int(not_nullable(semesters["year"][0]))
         dbSemester = get_first(select(Semester).where(Semester.label == semesterLabel, Semester.year == semesterYear))
 
         if dbSemester is None:
-            raise DataBaseImportException(
+            raise DatabaseImportException(
                 f"{semesterLabel}{semesterYear} does not exist in the database! Please make sure that you create the semester from the web interface first."
             )
 
@@ -164,7 +164,7 @@ def importFromFile(filePath: Path):
             )
 
             if dbPart is None:
-                raise DataBaseImportException(
+                raise DatabaseImportException(
                     f"Part with number {partNumber} and program label {partProgramLabel} does not exist in the database! Please make sure that you create parts from the web interface first."
                 )
 
@@ -179,7 +179,9 @@ def importFromFile(filePath: Path):
             first_name = not_nullable(students["first_name"][i])
             last_name = not_nullable(students["last_name"][i])
             uni_email = not_nullable(students["uni_email"][i]).lower()
-            contact_email = nullable(students["contact_email"][i]).lower()
+            contact_email = nullable(students["contact_email"][i])
+            if contact_email is not None:
+                contact_email = contact_email.lower()
             bachelor_thesis = nullable(students["bachelor_thesis"][i])
             bachelor_thesis_work_group = nullable(students["bachelor_thesis_work_group"][i])
             note = nullable(students["note"][i])
@@ -277,7 +279,7 @@ def importFromFile(filePath: Path):
 
             if dbExperiment is None:
                 # TODO: Check if experimentProgram is None
-                raise DataBaseImportException(
+                raise DatabaseImportException(
                     f"Experiment with number {experimentNumber} and program {experimentProgram} does not exist in the database. Please make sure that experiments are created from the web interface."
                 )
 
@@ -288,7 +290,7 @@ def importFromFile(filePath: Path):
             )
 
             if dbSemesterExperiment is None:
-                raise DataBaseImportException(
+                raise DatabaseImportException(
                     f"No semester experiment exists in the database to the experiment with number {experimentNumber} and program {experimentProgram}. Please make sure that semester experiments are created in the web interface. The problem might be that the experiment was not active while creating a new semester"
                 )
 
@@ -316,7 +318,7 @@ def importFromFile(filePath: Path):
             assistant = get_first(select(Assistant).join(User).where(User.email == assistantEmail))
 
             if assistant is None:
-                raise DataBaseImportException(
+                raise DatabaseImportException(
                     f"Assistant with email {assistantEmail} does not exist in the database! Please make sure that you create assistants in the web interface."
                 )
 
@@ -345,5 +347,5 @@ def importFromFile(filePath: Path):
 
     flash(f"Made a backup of the database after the import at {dest}")
 
-    flash("\nImport done!")
-    flash("Please check that everything worked as expected. Restore the database backup otherwise!")
+    flash("\nImport done!", "success")
+    flash("Please check that everything worked as expected. Restore the database backup otherwise!", "warning")
diff --git a/advlabdb/exceptions.py b/advlabdb/exceptions.py
index fe4c341..52d75b4 100644
--- a/advlabdb/exceptions.py
+++ b/advlabdb/exceptions.py
@@ -6,5 +6,5 @@ class DatabaseException(Exception):
     pass
 
 
-class DataBaseImportException(Exception):
+class DatabaseImportException(Exception):
     pass