diff --git a/umap/static/umap/js/modules/data/layer.js b/umap/static/umap/js/modules/data/layer.js
index 12086c1a..02692f57 100644
--- a/umap/static/umap/js/modules/data/layer.js
+++ b/umap/static/umap/js/modules/data/layer.js
@@ -249,6 +249,7 @@ export class DataLayer extends ServerStored {
   }
 
   fromGeoJSON(geojson, sync = true) {
+    if (!geojson) return []
     const features = this.addData(geojson, sync)
     this._geojson = geojson
     this.onDataLoaded()
@@ -319,7 +320,9 @@ export class DataLayer extends ServerStored {
     if (!this.isRemoteLayer()) return
     if (!this.hasDynamicData() && this.hasDataLoaded() && !force) return
     if (!this.isVisible()) return
-    let url = this._umap.renderUrl(this.options.remoteData.url)
+    // Keep non proxied url for later use in Alert.
+    const remoteUrl = this._umap.renderUrl(this.options.remoteData.url)
+    let url = remoteUrl
     if (this.options.remoteData.proxy) {
       url = this._umap.proxyUrl(url, this.options.remoteData.ttl)
     }
@@ -328,6 +331,14 @@ export class DataLayer extends ServerStored {
       return this._umap.formatter
         .parse(raw, this.options.remoteData.format)
         .then((geojson) => this.fromGeoJSON(geojson))
+        .catch((error) => {
+          Alert.error(
+            translate('Cannot parse remote data for layer "{layer}" with url "{url}"', {
+              layer: this.getName(),
+              url: remoteUrl,
+            })
+          )
+        })
     })
   }
 
@@ -455,7 +466,7 @@ export class DataLayer extends ServerStored {
       // otherwise the layer becomes uneditable.
       return this.makeFeatures(geojson, sync)
     } catch (err) {
-      console.log('Error with DataLayer', this.id)
+      console.debug('Error with DataLayer', this.id)
       console.error(err)
       return []
     }
@@ -502,7 +513,7 @@ export class DataLayer extends ServerStored {
         feature = new Polygon(this._umap, this, geojson, id)
         break
       default:
-        console.log(geojson)
+        console.debug(geojson)
         Alert.error(
           translate('Skipping unknown geometry.type: {type}', {
             type: geometry.type || 'undefined',
@@ -524,6 +535,9 @@ export class DataLayer extends ServerStored {
         if (data?.length) this.isDirty = true
         return data
       })
+      .catch((error) => {
+        Alert.error(translate('Import failed: invalid data'))
+      })
   }
 
   readFile(f) {
diff --git a/umap/static/umap/js/modules/formatter.js b/umap/static/umap/js/modules/formatter.js
index 6a03b6b5..314bf391 100644
--- a/umap/static/umap/js/modules/formatter.js
+++ b/umap/static/umap/js/modules/formatter.js
@@ -1,5 +1,6 @@
 /* Uses globals for: csv2geojson, osmtogeojson (not available as ESM) */
 import { translate } from './i18n.js'
+import { uMapAlert as Alert } from '../components/alerts/alert.js'
 
 export const EXPORT_FORMATS = {
   geojson: {
@@ -58,11 +59,7 @@ export class Formatter {
   }
 
   async fromGeoJSON(str) {
-    try {
-      return JSON.parse(str)
-    } catch (err) {
-      U.Alert.error(`Invalid JSON file: ${err}`)
-    }
+    return JSON.parse(str)
   }
 
   async fromOSM(str) {
@@ -106,8 +103,8 @@ export class Formatter {
               message: err[0].message,
             })
           }
-          U.Alert.error(message, 10000)
-          console.error(err)
+          Alert.error(message, 10000)
+          console.debug(err)
         }
         if (result?.features.length) {
           callback(result)
@@ -127,7 +124,7 @@ export class Formatter {
     const doc = new DOMParser().parseFromString(x, 'text/xml')
     const errorNode = doc.querySelector('parsererror')
     if (errorNode) {
-      U.Alert.error(translate('Cannot parse data'))
+      Alert.error(translate('Cannot parse data'))
     }
     return doc
   }
diff --git a/umap/static/umap/js/modules/importer.js b/umap/static/umap/js/modules/importer.js
index 268b1d15..7672dcdb 100644
--- a/umap/static/umap/js/modules/importer.js
+++ b/umap/static/umap/js/modules/importer.js
@@ -305,7 +305,7 @@ export default class Importer extends Utils.WithTemplate {
       this.onSuccess()
     } catch (e) {
       this.onError(translate('Invalid umap data'))
-      console.error(e)
+      console.debug(e)
       return false
     }
   }
diff --git a/umap/tests/integration/test_import.py b/umap/tests/integration/test_import.py
index f51d0967..57e9b73a 100644
--- a/umap/tests/integration/test_import.py
+++ b/umap/tests/integration/test_import.py
@@ -71,7 +71,6 @@ def test_umap_import_from_file(live_server, tilelayer, page):
     expect(nonloaded).to_have_count(1)
 
 
-@pytest.mark.skip
 def test_umap_import_from_textarea(live_server, tilelayer, page, settings):
     settings.UMAP_ALLOW_ANONYMOUS = True
     page.goto(f"{live_server.url}/map/new/")
@@ -123,6 +122,28 @@ def test_import_geojson_from_textarea(tilelayer, live_server, page):
     expect(paths).to_have_count(3)
 
 
+def test_import_invalid_data(tilelayer, live_server, page):
+    uncaught_errors = []
+    page.on("pageerror", lambda exc: uncaught_errors.append(exc))
+    page.goto(f"{live_server.url}/map/new/")
+    page.get_by_title("Open browser").click()
+    layers = page.locator(".umap-browser .datalayer")
+    markers = page.locator(".leaflet-marker-icon")
+    paths = page.locator("path")
+    expect(markers).to_have_count(0)
+    expect(paths).to_have_count(0)
+    expect(layers).to_have_count(0)
+    button = page.get_by_title("Import data")
+    expect(button).to_be_visible()
+    button.click()
+    textarea = page.locator(".umap-upload textarea")
+    textarea.fill("invalid data")
+    for format in ["geojson", "csv", "gpx", "kml", "georss", "osm", "umap"]:
+        page.locator('select[name="format"]').select_option(format)
+        page.get_by_role("button", name="Import data", exact=True).click()
+        assert not uncaught_errors, f"Error with format {format}"
+
+
 def test_import_kml_from_textarea(tilelayer, live_server, page):
     page.goto(f"{live_server.url}/map/new/")
     page.get_by_title("Open browser").click()