diff --git a/src/ClientServer/Controllers/Core/Exercises/DoExerciseController.cs b/src/ClientServer/Controllers/Core/Exercises/DoExerciseController.cs
index 6b4a521a254129403e311d580eab8aeb4841fc84..3766b4e2e2cdcbcd68744cfde063a1d7114e2ccb 100644
--- a/src/ClientServer/Controllers/Core/Exercises/DoExerciseController.cs
+++ b/src/ClientServer/Controllers/Core/Exercises/DoExerciseController.cs
@@ -1948,6 +1948,9 @@ namespace ClientServer.Controllers.Core.Exercises
                     }
                     else
                     {
+                        // IsContentVisibleForUser is ignored here so a user can have his own version
+                        // however, for all testing and other api paths we replace the not visible files with other content
+                        // keep it for compatibility (difficulties when IsContentVisibleForUser is changed)
                         if (oldTemplate.IsEditableByUser) //only modify if allowed
                         {
                             oldFile.Content = solutionFileForBackend.Content;