diff --git a/app/Helpers/Csv/Converter/AssetAccountIban.php b/app/Helpers/Csv/Converter/AssetAccountIban.php
index 2da18150a5..e10ceb344f 100644
--- a/app/Helpers/Csv/Converter/AssetAccountIban.php
+++ b/app/Helpers/Csv/Converter/AssetAccountIban.php
@@ -32,7 +32,7 @@ class AssetAccountIban extends BasicConverter implements ConverterInterface
 
             if (is_null($account)) {
                 // create it if doesn't exist.
-                $account = Account::firstOrCreateEncrypted(
+                $account = Account::firstOrCreateEncrypted( // TODO use repository
                     [
                         'name'            => $this->value,
                         'iban'            => $this->value,
diff --git a/app/Helpers/Csv/Converter/AssetAccountName.php b/app/Helpers/Csv/Converter/AssetAccountName.php
index ead84e19a6..14eb37d1c3 100644
--- a/app/Helpers/Csv/Converter/AssetAccountName.php
+++ b/app/Helpers/Csv/Converter/AssetAccountName.php
@@ -36,7 +36,7 @@ class AssetAccountName extends BasicConverter implements ConverterInterface
         }
 
         // create it if doesnt exist.
-        $account = Account::firstOrCreateEncrypted(
+        $account = Account::firstOrCreateEncrypted( // TODO use repository
             [
                 'name'            => $this->value,
                 'iban'            => '',
diff --git a/app/Helpers/Csv/Converter/BudgetName.php b/app/Helpers/Csv/Converter/BudgetName.php
index a5e87490b3..e2a017d483 100644
--- a/app/Helpers/Csv/Converter/BudgetName.php
+++ b/app/Helpers/Csv/Converter/BudgetName.php
@@ -22,7 +22,7 @@ class BudgetName extends BasicConverter implements ConverterInterface
         if (isset($this->mapped[$this->index][$this->value])) {
             $budget = Auth::user()->budgets()->find($this->mapped[$this->index][$this->value]);
         } else {
-            $budget = Budget::firstOrCreateEncrypted(
+            $budget = Budget::firstOrCreateEncrypted( // TODO use repository
                 [
                     'name'    => $this->value,
                     'user_id' => Auth::user()->id,
diff --git a/app/Helpers/Csv/Converter/CategoryName.php b/app/Helpers/Csv/Converter/CategoryName.php
index aff385378c..0f1fcc9ccb 100644
--- a/app/Helpers/Csv/Converter/CategoryName.php
+++ b/app/Helpers/Csv/Converter/CategoryName.php
@@ -22,7 +22,7 @@ class CategoryName extends BasicConverter implements ConverterInterface
         if (isset($this->mapped[$this->index][$this->value])) {
             $category = Auth::user()->categories()->find($this->mapped[$this->index][$this->value]);
         } else {
-            $category = Category::firstOrCreateEncrypted(
+            $category = Category::firstOrCreateEncrypted( // TODO use repository
                 [
                     'name'    => $this->value,
                     'user_id' => Auth::user()->id,
diff --git a/app/Helpers/Csv/Converter/Description.php b/app/Helpers/Csv/Converter/Description.php
index 8de2a48ece..98cfd1b4bf 100644
--- a/app/Helpers/Csv/Converter/Description.php
+++ b/app/Helpers/Csv/Converter/Description.php
@@ -16,6 +16,8 @@ class Description extends BasicConverter implements ConverterInterface
      */
     public function convert()
     {
-        return trim($this->data['description'] . ' ' . $this->value);
+        $description = $this->data['description'] ?? '';
+
+        return trim($description . ' ' . $this->value);
     }
 }
diff --git a/app/Helpers/Csv/Converter/TagsComma.php b/app/Helpers/Csv/Converter/TagsComma.php
index 65c420e1d2..fe1550036a 100644
--- a/app/Helpers/Csv/Converter/TagsComma.php
+++ b/app/Helpers/Csv/Converter/TagsComma.php
@@ -23,7 +23,7 @@ class TagsComma extends BasicConverter implements ConverterInterface
 
         $strings = explode(',', $this->value);
         foreach ($strings as $string) {
-            $tag = Tag::firstOrCreateEncrypted(
+            $tag = Tag::firstOrCreateEncrypted( // TODO use repository
                 [
                     'tag'     => $string,
                     'tagMode' => 'nothing',
diff --git a/app/Helpers/Csv/Converter/TagsSpace.php b/app/Helpers/Csv/Converter/TagsSpace.php
index 278277eed2..d371073679 100644
--- a/app/Helpers/Csv/Converter/TagsSpace.php
+++ b/app/Helpers/Csv/Converter/TagsSpace.php
@@ -23,7 +23,7 @@ class TagsSpace extends BasicConverter implements ConverterInterface
 
         $strings = explode(' ', $this->value);
         foreach ($strings as $string) {
-            $tag = Tag::firstOrCreateEncrypted(
+            $tag = Tag::firstOrCreateEncrypted( // TODO use repository
                 [
                     'tag'     => $string,
                     'tagMode' => 'nothing',
diff --git a/app/Helpers/Csv/Importer.php b/app/Helpers/Csv/Importer.php
index 7126eddefb..0df9e8656a 100644
--- a/app/Helpers/Csv/Importer.php
+++ b/app/Helpers/Csv/Importer.php
@@ -169,7 +169,7 @@ class Importer
 
             // second transaction
             $accountId   = $this->importData['opposing-account-object']->id; // create second transaction:
-            $amount      = bcmul($this->importData['amount'], -1);
+            $amount      = bcmul($this->importData['amount'], '-1');
             $transaction = Transaction::create(['transaction_journal_id' => $journal->id, 'account_id' => $accountId, 'amount' => $amount]);
             $errors      = $transaction->getErrors()->merge($errors);
         }
@@ -195,7 +195,7 @@ class Importer
 
         Log::info('Created journal #' . $journalId . ' of type ' . $type . '!');
         Log::info('Asset account #' . $asset->id . ' lost/gained: ' . $this->importData['amount']);
-        Log::info($opposing->accountType->type . ' #' . $opposing->id . ' lost/gained: ' . bcmul($this->importData['amount'], -1));
+        Log::info($opposing->accountType->type . ' #' . $opposing->id . ' lost/gained: ' . bcmul($this->importData['amount'], '-1'));
 
         return $journal;
     }
@@ -296,7 +296,8 @@ class Importer
         foreach ($set as $className) {
             /** @var PostProcessorInterface $postProcessor */
             $postProcessor = app('FireflyIII\Helpers\Csv\PostProcessing\\' . $className);
-            $postProcessor->setData($this->importData);
+            $array         = $this->importData ?? [];
+            $postProcessor->setData($array);
             Log::debug('Now post-process processor named ' . $className . ':');
             $this->importData = $postProcessor->process();
         }
@@ -343,7 +344,9 @@ class Importer
      */
     protected function validateData()
     {
-        if (is_null($this->importData['date']) && is_null($this->importData['date-rent'])) {
+        $date     = $this->importData['date'] ?? null;
+        $rentDate = $this->importData['date-rent'] ?? null;
+        if (is_null($date) && is_null($rentDate)) {
             return 'No date value for this row.';
         }
         if (is_null($this->importData['opposing-account-object'])) {
diff --git a/app/Helpers/Csv/PostProcessing/Amount.php b/app/Helpers/Csv/PostProcessing/Amount.php
index c542139542..336c69dfb9 100644
--- a/app/Helpers/Csv/PostProcessing/Amount.php
+++ b/app/Helpers/Csv/PostProcessing/Amount.php
@@ -20,7 +20,9 @@ class Amount implements PostProcessorInterface
     public function process()
     {
         bcscale(2);
-        $this->data['amount'] = bcmul($this->data['amount'], $this->data['amount-modifier']);
+        $amount               = $this->data['amount'] ?? '0';
+        $modifier             = strval($this->data['amount-modifier']);
+        $this->data['amount'] = bcmul($amount, $modifier);
 
         return $this->data;
     }
diff --git a/app/Helpers/Csv/PostProcessing/Description.php b/app/Helpers/Csv/PostProcessing/Description.php
index 15a0a649d8..64c0e8ed8b 100644
--- a/app/Helpers/Csv/PostProcessing/Description.php
+++ b/app/Helpers/Csv/PostProcessing/Description.php
@@ -18,7 +18,8 @@ class Description implements PostProcessorInterface
      */
     public function process()
     {
-        $this->data['description'] = trim($this->data['description']);
+        $description               = $this->data['description'] ?? '';
+        $this->data['description'] = trim($description);
         if (strlen($this->data['description']) == 0) {
             $this->data['description'] = trans('firefly.csv_empty_description');
         }
diff --git a/app/Helpers/Csv/PostProcessing/OpposingAccount.php b/app/Helpers/Csv/PostProcessing/OpposingAccount.php
index cbce96f679..969289a636 100644
--- a/app/Helpers/Csv/PostProcessing/OpposingAccount.php
+++ b/app/Helpers/Csv/PostProcessing/OpposingAccount.php
@@ -125,7 +125,7 @@ class OpposingAccount implements PostProcessorInterface
         // create if not exists:
         $name    = is_string($this->data['opposing-account-name']) && strlen($this->data['opposing-account-name']) > 0 ? $this->data['opposing-account-name']
             : $this->data['opposing-account-iban'];
-        $account = Account::firstOrCreateEncrypted(
+        $account = Account::firstOrCreateEncrypted( // TODO use repository
             [
                 'user_id'         => Auth::user()->id,
                 'account_type_id' => $accountType->id,
@@ -195,7 +195,7 @@ class OpposingAccount implements PostProcessorInterface
             }
         }
         // create if not exists:
-        $account = Account::firstOrCreateEncrypted(
+        $account = Account::firstOrCreateEncrypted( // TODO use repository
             [
                 'user_id'         => Auth::user()->id,
                 'account_type_id' => $accountType->id,
diff --git a/app/Helpers/Csv/Wizard.php b/app/Helpers/Csv/Wizard.php
index 2ee7efdacc..540f51a3c7 100644
--- a/app/Helpers/Csv/Wizard.php
+++ b/app/Helpers/Csv/Wizard.php
@@ -141,7 +141,7 @@ class Wizard implements WizardInterface
                 /** @var MapperInterface $mapObject */
                 $mapObject = app($class);
             } catch (ReflectionException $e) {
-                throw new FireflyException('Column "' . $columnRole . '" cannot be mapped because class ' . $mapper . ' does not exist.');
+                throw new FireflyException('Column "' . $columnRole . '" cannot be mapped because mapper class ' . $mapper . ' does not exist.');
             }
             $set             = $mapObject->getMap();
             $options[$index] = $set;
diff --git a/app/Http/Controllers/CsvController.php b/app/Http/Controllers/CsvController.php
index 9084eb39a0..261496d7de 100644
--- a/app/Http/Controllers/CsvController.php
+++ b/app/Http/Controllers/CsvController.php
@@ -219,8 +219,9 @@ class CsvController extends Controller
         }
 
         // process given roles and mapping:
+        $inputMap = Input::get('map') ?? [];
         $roles = $this->wizard->processSelectedRoles(Input::get('role'));
-        $maps  = $this->wizard->processSelectedMapping($roles, Input::get('map'));
+        $maps  = $this->wizard->processSelectedMapping($roles, $inputMap);
 
         Session::put('csv-map', $maps);
         Session::put('csv-roles', $roles);