diff --git a/src/aki_prj23_transparenzregister/ui/data_elements.py b/src/aki_prj23_transparenzregister/ui/data_elements.py
index 679ac40..106eecc 100644
--- a/src/aki_prj23_transparenzregister/ui/data_elements.py
+++ b/src/aki_prj23_transparenzregister/ui/data_elements.py
@@ -4,14 +4,13 @@ import pandas as pd
 import sqlalchemy as sa
 from cachetools import TTLCache, cached
 from loguru import logger
-from sqlalchemy.engine import Engine
 from sqlalchemy.orm import Session
 
 from aki_prj23_transparenzregister.utils.sql import entities
 
 
 def get_company_data(session: Session) -> pd.DataFrame:
-    """Creates a session to the database and get's all available company data.
+    """Creates a session to the database and collects all available company data.
 
     Args:
         session: A session connecting to the database.
@@ -23,14 +22,14 @@ def get_company_data(session: Session) -> pd.DataFrame:
         entities.DistrictCourt
     )
     engine = session.bind
-    if not isinstance(engine, Engine):
+    if not isinstance(engine, sa.engine.Engine):
         raise TypeError
 
     return pd.read_sql(str(query_company), engine, index_col="company_id")
 
 
 def get_person_data(session: Session) -> pd.DataFrame:
-    """Creates a session to the database and get's all available company data.
+    """Creates a session to the database and collects all available company data.
 
     Args:
         session: A session connecting to the database.
@@ -40,7 +39,7 @@ def get_person_data(session: Session) -> pd.DataFrame:
     """
     query_person = session.query(entities.Person)
     engine = session.bind
-    if not isinstance(engine, Engine):
+    if not isinstance(engine, sa.engine.Engine):
         raise TypeError
 
     return pd.read_sql(str(query_person), engine, index_col="person_id")
@@ -60,7 +59,7 @@ def get_finance_data(session: Session) -> pd.DataFrame:
     ).join(entities.Company)
 
     engine = session.bind
-    if not isinstance(engine, Engine):
+    if not isinstance(engine, sa.engine.Engine):
         raise TypeError
 
     return pd.read_sql(str(query_finance), engine)
@@ -85,9 +84,12 @@ def get_finance_data_of_one_company(session: Session, company_id: int) -> pd.Dat
         logger.warning("SQL rollback after operational Error!")
         session.rollback()
         annual_finance_data = query.all()
-
+    except sa.exc.PendingRollbackError:
+        logger.warning("SQL rollback when demanded!")
+        session.rollback()
+        annual_finance_data = query.all()
     engine = session.bind
-    if not isinstance(engine, Engine):
+    if not isinstance(engine, sa.engine.Engine):
         raise TypeError
 
     data = [row.__dict__ for row in annual_finance_data]