diff --git a/R/module_nested_tabs.R b/R/module_nested_tabs.R
index 59e819a2a0..978c5b3a33 100644
--- a/R/module_nested_tabs.R
+++ b/R/module_nested_tabs.R
@@ -336,33 +336,26 @@ srv_teal_module.teal_module <- function(id,
         data = data,
         is_active = is_active
       )
-      is_transform_failed <- reactiveValues()
       transformed_teal_data <- srv_transform_teal_data(
         "data_transform",
         data = filtered_teal_data,
         transformators = modules$transformators,
-        modules = modules,
-        is_transform_failed = is_transform_failed
+        modules = modules
       )
       any_transform_failed <- reactive({
-        any(unlist(reactiveValuesToList(is_transform_failed)))
+        !inherits(try(transformed_teal_data(), silent = TRUE), "teal_data") &&
+          inherits(filtered_teal_data(), "teal_data")
       })
 
       observeEvent(any_transform_failed(), {
-        if (isTRUE(any_transform_failed())) {
-          shinyjs::hide("teal_module_ui")
-          shinyjs::show("transform_failure_info")
-        } else {
-          shinyjs::show("teal_module_ui")
-          shinyjs::hide("transform_failure_info")
-        }
+        shinyjs::toggleElement("transform_failure_info", condition = any_transform_failed())
       })
 
-      module_teal_data <- reactive({
-        req(inherits(transformed_teal_data(), "teal_data"))
-        all_teal_data <- transformed_teal_data()
-        module_datanames <- .resolve_module_datanames(data = all_teal_data, modules = modules)
-        all_teal_data[c(module_datanames, ".raw_data")]
+      summary_data <- reactiveVal(NULL)
+      module_teal_data <- eventReactive(transformed_teal_data(), {
+        module_datanames <- .resolve_module_datanames(data = transformed_teal_data(), modules = modules)
+        summary_data(transformed_teal_data()[c(module_datanames, ".raw_data")])
+        summary_data()
       })
 
       srv_check_module_datanames(
@@ -371,7 +364,7 @@ srv_teal_module.teal_module <- function(id,
         modules = modules
       )
 
-      summary_table <- srv_data_summary("data_summary", module_teal_data)
+      summary_table <- srv_data_summary("data_summary", summary_data) # Only updates on success
 
       observeEvent(input$data_summary_toggle, {
         bslib::toggle_sidebar(id = "teal_module_sidebar", open = TRUE)
diff --git a/R/module_transform_data.R b/R/module_transform_data.R
index 26b49f0b47..7a82c9322e 100644
--- a/R/module_transform_data.R
+++ b/R/module_transform_data.R
@@ -37,9 +37,19 @@ ui_transform_teal_data <- function(id, transformators, class = "well") {
 
       display_fun(
         bslib::accordion(
+          id = ns("wrapper"),
+          class = "validation-wrapper",
           bslib::accordion_panel(
+            id = ns("wrapper_panel"),
+            class = "validation-panel",
             attr(data_mod, "label"),
             icon = bsicons::bs_icon("palette-fill"),
+            tags$div(
+              class = "disabled-info",
+              title = "Disabled until data becomes valid",
+              bsicons::bs_icon("info-circle"),
+              "Disabled until data becomes valid. Check your inputs."
+            ),
             tags$div(
               id = transform_wrapper_id,
               if (is.null(data_mod$ui)) {
@@ -62,7 +72,7 @@ ui_transform_teal_data <- function(id, transformators, class = "well") {
 
 #' @export
 #' @rdname module_transform_data
-srv_transform_teal_data <- function(id, data, transformators, modules = NULL, is_transform_failed = reactiveValues()) {
+srv_transform_teal_data <- function(id, data, transformators, modules = NULL) {
   checkmate::assert_string(id)
   assert_reactive(data)
   checkmate::assert_class(modules, "teal_module", null.ok = TRUE)
@@ -76,39 +86,47 @@ srv_transform_teal_data <- function(id, data, transformators, modules = NULL, is
   names(transformators) <- sprintf("transform_%d", seq_len(length(transformators)))
 
   moduleServer(id, function(input, output, session) {
+    data_original_handled <- reactive(tryCatch(data(), error = function(e) e))
     module_output <- Reduce(
       function(data_previous, name) {
         moduleServer(name, function(input, output, session) {
           logger::log_debug("srv_transform_teal_data@1 initializing module for { name }.")
-
           data_out <- reactiveVal()
+
+          # Disable all elements if original data is not yet a teal_data
+          observeEvent(data_original_handled(), {
+            shinyjs::toggleState(
+              "wrapper_panel",
+              condition = inherits(data_original_handled(), "teal_data")
+            )
+          })
+
           .call_once_when(inherits(data_previous(), "teal_data"), {
             logger::log_debug("srv_teal_transform_teal_data@2 triggering a transform module call for { name }.")
             data_unhandled <- transformators[[name]]$server("transform", data = data_previous)
             data_handled <- reactive(tryCatch(data_unhandled(), error = function(e) e))
 
-            observeEvent(data_handled(), {
-              if (inherits(data_handled(), "teal_data")) {
-                if (!identical(data_handled(), data_out())) {
+            observeEvent(
+              {
+                data_handled()
+                data_original_handled()
+              },
+              {
+                if (inherits(data_original_handled(), "condition")) {
+                  data_out(data_original_handled())
+                } else if (inherits(data_handled(), "teal_data")) {
+                  if (!identical(data_handled(), data_out())) {
+                    data_out(data_handled())
+                  }
+                } else {
                   data_out(data_handled())
                 }
               }
-            })
-
-            is_transform_failed[[name]] <- FALSE
-            observeEvent(data_handled(), {
-              if (inherits(data_handled(), "teal_data")) {
-                is_transform_failed[[name]] <- FALSE
-              } else {
-                is_transform_failed[[name]] <- TRUE
-              }
-            })
+            )
 
             is_previous_failed <- reactive({
-              idx_this <- which(names(is_transform_failed) == name)
-              is_transform_failed_list <- reactiveValuesToList(is_transform_failed)
-              idx_failures <- which(unlist(is_transform_failed_list))
-              any(idx_failures < idx_this)
+              inherits(data_original_handled(), "teal_data") &&
+                !inherits(try(data_previous(), silent = TRUE), "teal_data")
             })
 
             srv_validate_error("silent_error", data_handled, validate_shiny_silent_error = FALSE)
@@ -118,6 +136,7 @@ srv_transform_teal_data <- function(id, data, transformators, modules = NULL, is
             }
 
             # When there is no UI (`ui = NULL`) it should still show the errors
+            # It is a 1-way operation as there is no UI to correct the state
             observe({
               if (!inherits(data_handled(), "teal_data") && !is_previous_failed()) {
                 shinyjs::show("wrapper")
@@ -132,7 +151,7 @@ srv_transform_teal_data <- function(id, data, transformators, modules = NULL, is
                   "One of previous transformators failed. Please check its inputs.",
                   class = "teal-output-warning"
                 )
-              } else {
+              } else if (inherits(data_original_handled(), "teal_data")) {
                 shinyjs::enable(transform_wrapper_id)
                 shiny::tagList(
                   ui_validate_error(session$ns("silent_error")),
@@ -145,7 +164,8 @@ srv_transform_teal_data <- function(id, data, transformators, modules = NULL, is
 
           # Ignoring unwanted reactivity breaks during initialization
           reactive({
-            req(data_out())
+            validate(need(!inherits(data_out(), "condition"), message = data_out()$message)) # rethrow message
+            data_out()
           })
         })
       },
diff --git a/inst/css/validation.css b/inst/css/validation.css
index 665fac2d73..1734e73fe5 100644
--- a/inst/css/validation.css
+++ b/inst/css/validation.css
@@ -47,3 +47,31 @@
   border: 1px solid red;
   padding: 1em;
 }
+
+.validation-wrapper:has(.validation-panel[disabled="disabled"]) {
+  --bs-accordion-bg: var(--bs-gray-100);
+  background-color: var(--bs-gray-100);
+}
+
+.validation-wrapper:has(.validation-panel[disabled="disabled"]) .teal_validated,
+.validation-wrapper:has(.validation-panel[disabled="disabled"]) .shiny-output-error,
+.validation-wrapper:has(.validation-panel[disabled="disabled"]) .teal-output-warning {
+  display: none;
+}
+
+.validation-wrapper .disabled-info {
+  display: none;
+}
+
+.validation-wrapper .validation-panel[disabled="disabled"] {
+  padding-top: 0;
+}
+
+.validation-wrapper .validation-panel[disabled="disabled"] .disabled-info {
+  display: block;
+  border: 1px solid var(--bs-info);
+  border-radius: 4px;
+  padding: 1em;
+  color: color-mix(in srgb, var(--bs-info), black 20%);
+  background-color: color-mix(in srgb, var(--bs-info) 5%, transparent);
+}
diff --git a/man/module_transform_data.Rd b/man/module_transform_data.Rd
index fca1273403..28386f13d3 100644
--- a/man/module_transform_data.Rd
+++ b/man/module_transform_data.Rd
@@ -8,13 +8,7 @@
 \usage{
 ui_transform_teal_data(id, transformators, class = "well")
 
-srv_transform_teal_data(
-  id,
-  data,
-  transformators,
-  modules = NULL,
-  is_transform_failed = reactiveValues()
-)
+srv_transform_teal_data(id, data, transformators, modules = NULL)
 }
 \arguments{
 \item{id}{(\code{character(1)}) \code{shiny} module instance id.}
@@ -27,10 +21,6 @@ To learn more check \code{vignette("transform-input-data", package = "teal")}.}
 \item{data}{(\code{reactive} returning \code{teal_data})}
 
 \item{modules}{(\code{teal_modules} or \code{teal_module}) For \code{datanames} validation purpose}
-
-\item{is_transform_failed}{(\code{reactiveValues}) contains \code{logical} flags named after each transformator.
-Help to determine if any previous transformator failed, so that following transformators can be disabled
-and display a generic failure message.}
 }
 \value{
 \code{reactive} \code{teal_data}
diff --git a/teal.Rproj b/teal.Rproj
index ab99014abb..876e0b7f96 100644
--- a/teal.Rproj
+++ b/teal.Rproj
@@ -1,4 +1,5 @@
 Version: 1.0
+ProjectId: fa9b6a6c-a470-42a8-bc1a-165563e5ac01
 
 RestoreWorkspace: Default
 SaveWorkspace: Default