Solution 1:

Thank you a lot for posts like this that help us to advance step by step.

I've came up with other solution after i have tried the last one without success:

# OrmLite uses reflection
-keep class com.j256.**
-keepclassmembers class com.j256.** { *; }
-keep enum com.j256.**
-keepclassmembers enum com.j256.** { *; }
-keep interface com.j256.**
-keepclassmembers interface com.j256.** { *; }

I hope it can help someone.

Solution 2:

The accepted answer was not enough for my case, so I enhanced it and this is what I ended up with:

# OrmLite uses reflection
-keep class com.j256.**
-keepclassmembers class com.j256.** { *; }
-keep enum com.j256.**
-keepclassmembers enum com.j256.** { *; }
-keep interface com.j256.**
-keepclassmembers interface com.j256.** { *; }

# Keep the helper class and its constructor
-keep class * extends com.j256.ormlite.android.apptools.OrmLiteSqliteOpenHelper
-keepclassmembers class * extends com.j256.ormlite.android.apptools.OrmLiteSqliteOpenHelper {
  public <init>(android.content.Context);
}

# Keep the annotations
-keepattributes *Annotation*

# Keep all model classes that are used by OrmLite
# Also keep their field names and the constructor
-keep @com.j256.ormlite.table.DatabaseTable class * {
    @com.j256.ormlite.field.DatabaseField <fields>;
    @com.j256.ormlite.field.ForeignCollectionField <fields>;
    # Add the ormlite field annotations that your model uses here
    <init>();
}