isValid is optional and by default true

app/src/main/java/be/ugent/sel/studeez/common/composable/TextFieldComposable.kt

@@ -117,7 +117,7 @@ fun LabeledErrorTextField(
     initialValue: String,
     @StringRes label: Int,
     singleLine: Boolean = false,
-    isValid: MutableState<Boolean>,
+    isValid: MutableState<Boolean> = remember { mutableStateOf(true) },
     isFirst: MutableState<Boolean> = remember { mutableStateOf(false) },
     @StringRes errorText: Int,
     keyboardType: KeyboardType,

app/src/main/java/be/ugent/sel/studeez/screens/timer_form/form_screens/BreakTimerFormScreen.kt

@@ -30,6 +30,7 @@ class BreakTimerFormScreen(
             initialValue = breakTimerInfo.repeats.toString(),
             label = R.string.repeats,
             errorText = AppText.repeats_error,
+            isValid = mutableStateOf(false),
             keyboardType = KeyboardType.Decimal,
             predicate = { it.matches(Regex("[1-9]+\\d*")) }
         ) { correctlyTypedInt ->