diff --git a/app/Support/Nmr/DatasetSpectraInfoExtractor.php b/app/Support/Nmr/DatasetSpectraInfoExtractor.php
index b70c56b7..775a0f88 100644
--- a/app/Support/Nmr/DatasetSpectraInfoExtractor.php
+++ b/app/Support/Nmr/DatasetSpectraInfoExtractor.php
@@ -156,15 +156,12 @@ private function buildSearchText(array $info): string
         $parts = [];
 
         foreach ($info as $key => $value) {
-            if ($value === null || $value === '') {
+            $flattened = $this->flattenForSearch($value);
+            if ($flattened === '') {
                 continue;
             }
 
-            if (is_array($value)) {
-                $parts[] = $key.' '.implode(' ', array_map('strval', $value));
-            } else {
-                $parts[] = $key.' '.(string) $value;
-            }
+            $parts[] = $key.' '.$flattened;
         }
 
         $parts[] = json_encode($info, JSON_UNESCAPED_UNICODE) ?: '';
@@ -174,6 +171,39 @@ private function buildSearchText(array $info): string
         return $normalized ?? '';
     }
 
+    /**
+     * Recursively stringify scalars so nested NMRium arrays (2D frequencies,
+     * filters, meta) never trigger "Array to string conversion".
+     */
+    private function flattenForSearch(mixed $value): string
+    {
+        if ($value === null || $value === '') {
+            return '';
+        }
+
+        if (is_bool($value)) {
+            return $value ? '1' : '';
+        }
+
+        if (is_array($value)) {
+            $parts = [];
+            foreach ($value as $item) {
+                $flattened = $this->flattenForSearch($item);
+                if ($flattened !== '') {
+                    $parts[] = $flattened;
+                }
+            }
+
+            return implode(' ', $parts);
+        }
+
+        if (! is_scalar($value)) {
+            return '';
+        }
+
+        return trim((string) $value);
+    }
+
     private function property(array $info, string $key): mixed
     {
         return $info[$key] ?? null;
@@ -185,20 +215,56 @@ private function normalizeString(mixed $value): ?string
             return null;
         }
 
+        if (is_array($value)) {
+            foreach ($this->scalarLeaves($value) as $leaf) {
+                $normalized = $this->normalizeString($leaf);
+                if ($normalized !== null) {
+                    return $normalized;
+                }
+            }
+
+            return null;
+        }
+
+        if (is_bool($value) || ! is_scalar($value)) {
+            return null;
+        }
+
         $string = trim((string) $value);
 
         return $string === '' ? null : $string;
     }
 
+    /**
+     * @return list<int|float|string|bool>
+     */
+    private function scalarLeaves(array $value): array
+    {
+        $leaves = [];
+
+        array_walk_recursive($value, function (mixed $item) use (&$leaves): void {
+            if (is_scalar($item)) {
+                $leaves[] = $item;
+            }
+        });
+
+        return $leaves;
+    }
+
     private function normalizeNucleus(mixed $value): ?string
+    {
+        return $this->normalizeString($value);
+    }
+
+    private function normalizeDecimal(mixed $value): ?string
     {
         if ($value === null || $value === '') {
             return null;
         }
 
         if (is_array($value)) {
-            foreach ($value as $item) {
-                $normalized = $this->normalizeString($item);
+            foreach ($this->scalarLeaves($value) as $leaf) {
+                $normalized = $this->normalizeDecimal($leaf);
                 if ($normalized !== null) {
                     return $normalized;
                 }
@@ -207,15 +273,6 @@ private function normalizeNucleus(mixed $value): ?string
             return null;
         }
 
-        return $this->normalizeString($value);
-    }
-
-    private function normalizeDecimal(mixed $value): ?string
-    {
-        if ($value === null || $value === '') {
-            return null;
-        }
-
         if (! is_numeric($value)) {
             return null;
         }
@@ -229,6 +286,17 @@ private function normalizeInteger(mixed $value): ?int
             return null;
         }
 
+        if (is_array($value)) {
+            foreach ($this->scalarLeaves($value) as $leaf) {
+                $normalized = $this->normalizeInteger($leaf);
+                if ($normalized !== null) {
+                    return $normalized;
+                }
+            }
+
+            return null;
+        }
+
         if (! is_numeric($value)) {
             return null;
         }
@@ -245,7 +313,7 @@ private function normalizeSmallInteger(mixed $value): ?int
 
     private function normalizeBoolean(mixed $value): ?bool
     {
-        if ($value === null || $value === '') {
+        if ($value === null || $value === '' || is_array($value)) {
             return null;
         }
 
@@ -257,6 +325,10 @@ private function normalizeBoolean(mixed $value): ?bool
             return (bool) $value;
         }
 
+        if (! is_scalar($value)) {
+            return null;
+        }
+
         $normalized = strtolower(trim((string) $value));
 
         return match ($normalized) {
@@ -365,10 +437,25 @@ private function normalizeTubeDiameter(mixed $value): ?string
             return null;
         }
 
+        if (is_array($value)) {
+            foreach ($this->scalarLeaves($value) as $leaf) {
+                $normalized = $this->normalizeTubeDiameter($leaf);
+                if ($normalized !== null) {
+                    return $normalized;
+                }
+            }
+
+            return null;
+        }
+
         if (is_numeric($value)) {
             return (string) (int) round((float) $value);
         }
 
+        if (! is_scalar($value)) {
+            return null;
+        }
+
         $string = strtolower(trim((string) $value));
 
         if (preg_match('/(\d+(?:\.\d+)?)\s*mm?/', $string, $matches) === 1) {
diff --git a/tests/Unit/Support/DatasetSpectraInfoExtractorTest.php b/tests/Unit/Support/DatasetSpectraInfoExtractorTest.php
index 0e307a24..4026fbd0 100644
--- a/tests/Unit/Support/DatasetSpectraInfoExtractorTest.php
+++ b/tests/Unit/Support/DatasetSpectraInfoExtractorTest.php
@@ -303,6 +303,57 @@ public function test_extract_falls_back_to_jcamp_when_no_vendor_metadata(): void
         $this->assertSame('JCAMP', $payload['spectra_manufacturer']);
     }
 
+    public function test_extract_handles_nested_arrays_without_array_to_string_error(): void
+    {
+        $dataset = $this->makeDataset();
+
+        NMRium::factory()->forDataset($dataset)->create([
+            'nmrium_info' => [
+                'data' => [
+                    'spectra' => [
+                        [
+                            'info' => [
+                                'solvent' => 'CDCl3',
+                                'nucleus' => ['1H', '13C'],
+                                'experiment' => ['HSQC'],
+                                'probeName' => ['name' => 'BBO'],
+                                'originFrequency' => [600.13, 150.9],
+                                'baseFrequency' => [600.13, 150.9],
+                                'spectralWidth' => [16.02, 220.0],
+                                'numberOfPoints' => [2048, 512],
+                                'filters' => [
+                                    [
+                                        'name' => 'shift2D',
+                                        'value' => ['shift' => [0, 0]],
+                                    ],
+                                ],
+                                'meta' => [
+                                    'instrument' => ['vendor' => 'Bruker'],
+                                ],
+                            ],
+                        ],
+                    ],
+                ],
+            ],
+        ]);
+
+        $dataset->refresh();
+
+        $payload = $this->extractor->extractForDataset($dataset);
+
+        $this->assertSame('CDCl3', $payload['spectra_solvent']);
+        $this->assertSame('1H', $payload['spectra_nucleus']);
+        $this->assertSame('HSQC', $payload['spectra_experiment']);
+        $this->assertSame('BBO', $payload['spectra_probe_name']);
+        $this->assertSame('600.13', $payload['spectra_origin_frequency']);
+        $this->assertSame('600.13', $payload['spectra_base_frequency']);
+        $this->assertSame('16.02', $payload['spectra_spectral_width']);
+        $this->assertSame(2048, $payload['spectra_number_of_points']);
+        $this->assertNotNull($payload['spectra_info_extracted_at']);
+        $this->assertStringContainsString('bruker', strtolower($payload['spectra_search_text']));
+        $this->assertStringContainsString('hsqc', $payload['spectra_search_text']);
+    }
+
     public function test_extract_returns_empty_payload_when_no_nmrium_info(): void
     {
         $dataset = $this->makeDataset();