diff --git a/docroot/schema/event_layers.schema.json b/docroot/schema/event_layers.schema.json
index 82c56b56..1ccc27e2 100644
--- a/docroot/schema/event_layers.schema.json
+++ b/docroot/schema/event_layers.schema.json
@@ -34,7 +34,7 @@
                                 "type": "array",
                                 "items": {
                                     "type": "string",
-                                    "pattern": "^[\\\\()a-zA-Z0-9_-]+$",
+                                    "pattern": "^[\\\\()a-zA-Z0-9_+-]+$",
                                     "minLength": 1,
                                     "maxLength": 60
                                 }
diff --git a/src/Validation/InputValidator.php b/src/Validation/InputValidator.php
index 9263b1f4..de2648f3 100644
--- a/src/Validation/InputValidator.php
+++ b/src/Validation/InputValidator.php
@@ -448,6 +448,10 @@ public static function checkJsonSchema(array $json_fields, array &$params) {
 
             if (!$result->isValid()) {
                 $error = (new ErrorFormatter())->format($result->error());
+                $exc = new InvalidArgumentException("Invalid JSON: " . print_r($error, true) . "\n\n" . print_r($data, true));
+                // Log the error to disk so we can debug later
+                include_once HV_ROOT_DIR.'/../src/Helper/ErrorHandler.php';
+                logException($exc, "SchemaValidation_");
                 throw new InvalidArgumentException("Invalid JSON: " . print_r($error, true));
             }
         }
diff --git a/tests/unit_tests/validation/test_data/client_state/valid/valid_17.json b/tests/unit_tests/validation/test_data/client_state/valid/valid_17.json
new file mode 100644
index 00000000..6053161f
--- /dev/null
+++ b/tests/unit_tests/validation/test_data/client_state/valid/valid_17.json
@@ -0,0 +1,259 @@
+{
+  "date": 1410269529000,
+  "imageScale": 4.84088176,
+  "centerX": -2894.0322215830834,
+  "centerY": 101.72638697583727,
+  "imageLayers": [
+    {
+      "end": "2024-07-29 17:33:45",
+      "start": "2010-06-02 00:05:36",
+      "opacity": 100,
+      "visible": true,
+      "diffTime": 1,
+      "nickname": "AIA 171",
+      "sourceId": 10,
+      "uiLabels": [
+        {
+          "label": "Observatory",
+          "name": "SDO"
+        },
+        {
+          "label": "Instrument",
+          "name": "AIA"
+        },
+        {
+          "label": "Measurement",
+          "name": "171"
+        }
+      ],
+      "diffCount": 60,
+      "Instrument": "AIA",
+      "difference": 0,
+      "Measurement": "171",
+      "Observatory": "SDO",
+      "baseDiffTime": "2024-07-19T13:28:50.000Z",
+      "layeringOrder": 1
+    }
+  ],
+  "eventLayers": {
+    "tree_HEK": {
+      "id": "HEK",
+      "layers": [
+        {
+          "event_type": "AR",
+          "frms": [
+            "HMI_SHARP",
+            "NOAA_SWPC_Observer",
+            "SPoCA"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "CC",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "CD",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "CH",
+          "frms": [
+            "SPoCA"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "CJ",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "CE",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "CR",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "CW",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "EF",
+          "frms": [
+            "Emerging_flux_region_module"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "ER",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "FI",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "FA",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "FE",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "FL",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "LP",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "OS",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "PG",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "SG",
+          "frms": [
+            "Sigmoid_Sniffer"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "SP",
+          "frms": [
+            "all"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "SS",
+          "frms": [
+            "EGSO_SFC"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "TO",
+          "frms": [
+            "SSW_PFSS_v2_\\+_null_point_finder_v20180808"
+          ],
+          "event_instances": [],
+          "open": 1
+        }
+      ],
+      "visible": true,
+      "labels_visible": true,
+      "markers_visible": true,
+      "layer_available_visible": true
+    },
+    "tree_CCMC": {
+      "id": "CCMC",
+      "layers": [
+        {
+          "event_type": "C3",
+          "frms": [
+            "CME"
+          ],
+          "event_instances": [],
+          "open": 1
+        },
+        {
+          "event_type": "FP",
+          "frms": [
+            "MAG4_LoS_FEr"
+          ],
+          "event_instances": [],
+          "open": 1
+        }
+      ],
+      "visible": true,
+      "labels_visible": true,
+      "markers_visible": true,
+      "layer_available_visible": true
+    },
+    "tree_RHESSI": {
+      "id": "RHESSI",
+      "layers": [],
+      "visible": true,
+      "labels_visible": true,
+      "markers_visible": true,
+      "layer_available_visible": true
+    }
+  },
+  "celestialBodies": {
+    "soho": [],
+    "stereo_a": [
+      "stereo_a-mercury-tree-label"
+    ],
+    "stereo_b": []
+  }
+}