diff --git a/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupAccount_v4.java b/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupAccount_v4.java
index 1bb6d4aa6a148ce62897f1b6832c792cc6e53fd1..a6c890fb16ed59c26548c51ed63223e5952cf406 100644
--- a/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupAccount_v4.java
+++ b/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupAccount_v4.java
@@ -15,6 +15,7 @@ public class BackupAccount_v4 implements Upgradeable<BackupAccount_v5>
 
 	public BackupAccount_v4()
 	{
+		// for GSON
 	}
 
 	public BackupAccount_v4(Integer ID, String name, AccountType type)
diff --git a/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupCategory_v4.java b/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupCategory_v4.java
index d54af3e74c578eaa653873deded9d5e90bb733b1..deb61fbe872351eb6d1d00e8603ae11937e79873 100644
--- a/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupCategory_v4.java
+++ b/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupCategory_v4.java
@@ -15,6 +15,7 @@ public class BackupCategory_v4 implements Upgradeable<BackupCategory_v5>
 
 	public BackupCategory_v4()
 	{
+		// for GSON
 	}
 
 	public BackupCategory_v4(Integer ID, String name, String color, CategoryType type)
diff --git a/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupDatabase_v4.java b/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupDatabase_v4.java
index ee3cd62229bf8c9b82482887a0ade02e9ca03580..f5d408500c1a19de878206ff8ad0388af7d26c91 100644
--- a/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupDatabase_v4.java
+++ b/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupDatabase_v4.java
@@ -24,6 +24,7 @@ public class BackupDatabase_v4 implements BackupDatabase
 
 	public BackupDatabase_v4()
 	{
+		// for GSON
 	}
 
 	public BackupDatabase_v4(List<BackupCategory_v4> categories, List<BackupAccount_v4> accounts, List<BackupTransaction_v4> transactions, List<BackupTemplate_v4> templates)
diff --git a/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupRepeatingModifier_v4.java b/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupRepeatingModifier_v4.java
index 152cd6f105c763aa92e33495b6a997b676eda735..c50f252c2475660829750b774fbddddac186c813 100644
--- a/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupRepeatingModifier_v4.java
+++ b/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupRepeatingModifier_v4.java
@@ -9,6 +9,7 @@ public class BackupRepeatingModifier_v4
 
 	public BackupRepeatingModifier_v4()
 	{
+		// for GSON
 	}
 
 	public BackupRepeatingModifier_v4(Integer quantity, String localizationKey)
diff --git a/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupRepeatingOption_v4.java b/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupRepeatingOption_v4.java
index 821f8e0e13c20b1be97d842b0061438643d64276..bc439b09c085d35b1b75fc6783b07ddb44047992 100644
--- a/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupRepeatingOption_v4.java
+++ b/src/main/java/de/deadlocker8/budgetmaster/database/model/v4/BackupRepeatingOption_v4.java
@@ -10,6 +10,7 @@ public class BackupRepeatingOption_v4
 
 	public BackupRepeatingOption_v4()
 	{
+		// for GSON
 	}
 
 	public BackupRepeatingOption_v4(String startDate, BackupRepeatingModifier_v4 modifier, BackupRepeatingEndOption_v4 endOption)
diff --git a/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupAccount_v5.java b/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupAccount_v5.java
index 7a84fff6bae0c1ba355bf571ee40c0412931784b..2c4b8b52c0922b24cc4883401b33b525aaf20e7b 100644
--- a/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupAccount_v5.java
+++ b/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupAccount_v5.java
@@ -15,6 +15,7 @@ public class BackupAccount_v5
 
 	public BackupAccount_v5()
 	{
+		// for GSON
 	}
 
 	public BackupAccount_v5(Integer ID, String name, AccountState accountState, AccountType type, BackupImage_v5 icon)
diff --git a/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupCategory_v5.java b/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupCategory_v5.java
index 0d3d9edd9e31c809d6df772b7e9851f0262bbc8e..44591eee0af5a1d7f1107c592ed321e70047480d 100644
--- a/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupCategory_v5.java
+++ b/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupCategory_v5.java
@@ -14,6 +14,7 @@ public class BackupCategory_v5
 
 	public BackupCategory_v5()
 	{
+		// for GSON
 	}
 
 	public BackupCategory_v5(Integer ID, String name, String color, CategoryType type, String icon)
diff --git a/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupChart_v5.java b/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupChart_v5.java
index 7f336ea845192188aaa44ee693c1414ca7bcee49..6b152774954df768bd840679c377fe5a2187f0c9 100644
--- a/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupChart_v5.java
+++ b/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupChart_v5.java
@@ -14,6 +14,7 @@ public class BackupChart_v5
 
 	public BackupChart_v5()
 	{
+		// for GSON
 	}
 
 	public BackupChart_v5(Integer ID, String name, String script, ChartType type, int version)
diff --git a/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupDatabase_v5.java b/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupDatabase_v5.java
index f8854fb4734c32ff57f225be4d8abe9e4189afc5..6e8700a52636026fc8b6f56ac823c4398d02f63b 100644
--- a/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupDatabase_v5.java
+++ b/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupDatabase_v5.java
@@ -32,6 +32,7 @@ public class BackupDatabase_v5 implements BackupDatabase
 
 	public BackupDatabase_v5()
 	{
+		// for GSON
 	}
 
 	public BackupDatabase_v5(List<BackupCategory_v5> categories, List<BackupAccount_v5> accounts, List<BackupTransaction_v5> transactions, List<BackupTemplate_v5> templates, List<BackupChart_v5> charts, List<BackupImage_v5> images)
diff --git a/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupImage_v5.java b/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupImage_v5.java
index 288cbba8d40c4532d96b0738723004604fab7bff..44517e9ed9c982de7ccfe0b71a51022ff47f5799 100644
--- a/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupImage_v5.java
+++ b/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupImage_v5.java
@@ -13,6 +13,7 @@ public class BackupImage_v5
 
 	public BackupImage_v5()
 	{
+		// for GSON
 	}
 
 	public BackupImage_v5(Integer ID, Byte[] image, String fileName, ImageFileExtension fileExtension)
diff --git a/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupTemplate_v5.java b/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupTemplate_v5.java
index c58bf11cd4ee1886979ee7a5b6271e36ab88f65e..944f1090ac2a1fdcb50e37d15f804fd5cc21bfd0 100644
--- a/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupTemplate_v5.java
+++ b/src/main/java/de/deadlocker8/budgetmaster/database/model/v5/BackupTemplate_v5.java
@@ -20,6 +20,7 @@ public class BackupTemplate_v5
 
 	public BackupTemplate_v5()
 	{
+		// for GSON
 	}
 
 	public BackupTemplate_v5(String templateName, Integer amount, Boolean isExpenditure, BackupAccount_v5 account, BackupCategory_v5 category, String name, String description, BackupImage_v5 icon, List<Tag> tags, BackupAccount_v5 transferAccount)