diff --git a/ENI2/Controls/MaerskListControl.xaml.cs b/ENI2/Controls/MaerskListControl.xaml.cs
index c41b3386..b9a50030 100644
--- a/ENI2/Controls/MaerskListControl.xaml.cs
+++ b/ENI2/Controls/MaerskListControl.xaml.cs
@@ -279,8 +279,15 @@ namespace ENI2.Controls
                     md.MessageCore = core;
                     md.MessageCoreId = core.Id.Value;
                     this.UpdateStatus(md);
-                    if(!maerskDataList.Contains(md)) // DatabaseEntity implements IEquatable
+                    if (!maerskDataList.Contains(md)) // DatabaseEntity implements IEquatable
+                    { 
                         this.maerskDataList.Add(md);
+                        if(!core.VisitId.IsNullOrEmpty() && md.ColM.IsNullOrEmpty())
+                        {
+                            md.ColM = core.VisitId; // this can happen if client is closed before an Id has been returned, so we have to manually set it here
+                            Task<int> saveResult = DBManagerAsync.SaveAsync(md); // actually we do not need to await this
+                        }
+                    }
                 }
             }
             this.TimeFilterItemSource();
@@ -370,6 +377,7 @@ namespace ENI2.Controls
                     List<MaerskData> importData = new List<MaerskData>();
                     uint emptyRowCnt = 0;
                     bool isFirstRow = true;
+                    int currentRow = 1;
 
                     try
                     {
@@ -424,12 +432,29 @@ namespace ENI2.Controls
                             if (!reader.IsDBNull(12)) md.ColM = ReadFieldAsString(reader, 12);
                             if (!reader.IsDBNull(13)) md.Remark = ReadFieldAsString(reader, 13);
 
-                            if (!md.ColF.IsNullOrEmpty()) // only add this if IMO is set
+                            bool imoIsOkay = false;
+                            if(!md.ColF.IsNullOrEmpty())
+                            {
+                                if (Int32.TryParse(md.ColF, out int imo))
+                                {
+                                    if ((imo > 1000000) && (imo < 9999999))
+                                    {
+                                        imoIsOkay = true;
+                                    }
+                                }
+                                if(!imoIsOkay)
+                                {
+                                    MessageBox.Show($"Invalid IMO in row {currentRow}, skipping entry", Properties.Resources.textCaptionError, MessageBoxButton.OK, MessageBoxImage.Error);
+                                }
+                            }                            
+
+                            if (imoIsOkay)
                                 importData.Add(md);
                             else
                                 emptyRowCnt++;
                             if (emptyRowCnt > MAX_EMPTY_ROWS_ON_IMPORT) break;
                             if (isFirstRow) isFirstRow = false;
+                            currentRow++;
                         }
                     }
                     catch (Exception ex)