diff --git a/src/Dev/Deprecation.php b/src/Dev/Deprecation.php
index 81d9be590b3..16c94b02575 100644
--- a/src/Dev/Deprecation.php
+++ b/src/Dev/Deprecation.php
@@ -144,6 +144,9 @@ public static function withSuppressedNotice(callable $func): mixed
      */
     protected static function get_called_method_from_trace($backtrace, $level = 1)
     {
+        if ($backtrace === null) {
+            return '';
+        }
         $level = (int)$level;
         if (!$level) {
             $level = 1;
@@ -188,8 +191,11 @@ private static function get_called_from_trace(array $backtrace, int $level): arr
         return $called;
     }
 
-    private static function isCalledFromSupportedCode(array $backtrace): bool
+    private static function isCalledFromSupportedCode(?array $backtrace): bool
     {
+        if ($backtrace === null) {
+            return false;
+        }
         $called = Deprecation::get_called_from_trace($backtrace, 1);
         $file = $called['file'] ?? '';
         if (!$file) {
diff --git a/src/Forms/Form.php b/src/Forms/Form.php
index 07c4fc9eda2..c53d6d51d7a 100644
--- a/src/Forms/Form.php
+++ b/src/Forms/Form.php
@@ -1338,32 +1338,8 @@ public function validate(): ValidationResult
      * form that has some fields that save to one object, and some that save to another.
      * @return $this
      */
-    public function loadDataFrom($data, $mergeStrategy = 0, $fieldList = null)
+    public function loadDataFrom(object|array $data, int $mergeStrategy = 0, array $fieldList = [])
     {
-        if (!is_object($data) && !is_array($data)) {
-            user_error("Form::loadDataFrom() not passed an array or an object", E_USER_WARNING);
-            return $this;
-        }
-
-        // Handle the backwards compatible case of passing "true" as the second argument
-        if ($mergeStrategy === true) {
-            Deprecation::notice(
-                '5.4.0',
-                'Passing `true` to the $mergeStrategy argument in ' . Form::class . '::loadDataFrom() is deprecated.'
-                    . ' Pass ' . Form::class . '::MERGE_CLEAR_MISSING instead.',
-                Deprecation::SCOPE_GLOBAL
-            );
-            $mergeStrategy = Form::MERGE_CLEAR_MISSING;
-        } elseif ($mergeStrategy === false) {
-            Deprecation::notice(
-                '5.4.0',
-                'Passing `false` to the $mergeStrategy argument in ' . Form::class . '::loadDataFrom() is deprecated.'
-                    . ' Pass 0 instead.',
-                Deprecation::SCOPE_GLOBAL
-            );
-            $mergeStrategy = 0;
-        }
-
         // If an object is passed, save it for historical reference through {@link getRecord()}
         // Also use this to determine if we are loading a submitted form, or loading
         // from a record
@@ -1392,7 +1368,7 @@ public function loadDataFrom($data, $mergeStrategy = 0, $fieldList = null)
             $name = $field->getName();
 
             // Skip fields that have been excluded
-            if ($fieldList && !in_array($name, $fieldList ?? [])) {
+            if (!empty($fieldList) && !in_array($name, $fieldList)) {
                 continue;
             }
 
diff --git a/src/Forms/SearchableDropdownField.php b/src/Forms/SearchableDropdownField.php
index 5f459ad6634..371b527f491 100644
--- a/src/Forms/SearchableDropdownField.php
+++ b/src/Forms/SearchableDropdownField.php
@@ -27,18 +27,6 @@ public function __construct(
         $this->setHasEmptyDefault(true);
     }
 
-    /**
-     * @param string $string
-     * @return $this
-     *
-     * @deprecated 5.2.0 Use setPlaceholder() instead
-     */
-    public function setEmptyString($string)
-    {
-        Deprecation::notice('5.2.0', 'Use setPlaceholder() instead');
-        return parent::setEmptyString($string);
-    }
-
     public function getValueForValidation(): mixed
     {
         $arr = $this->getValueArray();
diff --git a/src/Forms/SearchableDropdownTrait.php b/src/Forms/SearchableDropdownTrait.php
index a01697aabf2..b5d794726db 100644
--- a/src/Forms/SearchableDropdownTrait.php
+++ b/src/Forms/SearchableDropdownTrait.php
@@ -158,8 +158,7 @@ public function getPlaceholder(): string
      * Calling this will also call setHasEmptyDefault(true), if the method exists on the class,
      * which is required for the placeholder functionality to work on SearchableDropdownField
      *
-     * In the case of SearchableDropField this method should be used instead of setEmptyString() which
-     * will be remvoved in a future version
+     * In the case of SearchableDropField this method should be used instead of setEmptyString()
      */
     public function setPlaceholder(string $placeholder): static
     {
diff --git a/src/ORM/Connect/MySQLDatabase.php b/src/ORM/Connect/MySQLDatabase.php
index 075c44eaf4f..45efc2482ea 100644
--- a/src/ORM/Connect/MySQLDatabase.php
+++ b/src/ORM/Connect/MySQLDatabase.php
@@ -207,16 +207,9 @@ public function searchEngine(
             }
         }
 
-        // Always ensure that only pages with ShowInSearch = 1 can be searched
+        // Always ensure that only pages/files with ShowInSearch = 1 can be searched
         $extraFilters[$pageClass] .= " AND ShowInSearch <> 0";
-
-        // File.ShowInSearch was added later, keep the database driver backwards compatible
-        // by checking for its existence first
-        $fileTable = DataObject::getSchema()->tableName($fileClass);
-        $fields = $this->getSchemaManager()->fieldList($fileTable);
-        if (array_key_exists('ShowInSearch', $fields ?? [])) {
-            $extraFilters[$fileClass] .= " AND ShowInSearch <> 0";
-        }
+        $extraFilters[$fileClass] .= " AND ShowInSearch <> 0";
 
         $limit = (int)$start . ", " . (int)$pageLength;
 
diff --git a/src/ORM/Connect/MySQLiConnector.php b/src/ORM/Connect/MySQLiConnector.php
index e480f5db9bf..2c60d57ca1f 100644
--- a/src/ORM/Connect/MySQLiConnector.php
+++ b/src/ORM/Connect/MySQLiConnector.php
@@ -315,7 +315,12 @@ public function preparedQuery($sql, $parameters, $errorLevel = E_USER_ERROR)
             }
 
             // Safely execute the statement
-            $statement->execute();
+            try {
+                $statement->execute();
+            } catch (mysqli_sql_exception $e) {
+                $success = false;
+                $this->databaseError($e->getMessage(), E_USER_ERROR, $sql, $parameters);
+            }
         }
 
         if (!$success || $statement->error) {
diff --git a/src/ORM/DataObject.php b/src/ORM/DataObject.php
index 28da655b35b..2f0903d4c9b 100644
--- a/src/ORM/DataObject.php
+++ b/src/ORM/DataObject.php
@@ -2682,21 +2682,7 @@ public function getCMSActions()
     public function getCMSCompositeValidator(): CompositeValidator
     {
         $compositeValidator = CompositeValidator::create();
-
-        // Support for the old method during the deprecation period
-        if ($this->hasMethod('getCMSValidator')) {
-            Deprecation::notice(
-                '5.4.0',
-                'The getCMSValidator() method is deprecated and won\'t be supported in a future major release.'
-                    . ' Override getCMSCompositeValidator() instead.',
-                Deprecation::SCOPE_GLOBAL
-            );
-            $compositeValidator->addValidator($this->getCMSValidator());
-        }
-
-        // Extend validator - forward support, will be supported beyond 5.0.0
         $this->invokeWithExtensions('updateCMSCompositeValidator', $compositeValidator);
-
         return $compositeValidator;
     }
 
diff --git a/tests/php/Forms/GridField/GridFieldDetailFormTest/Person.php b/tests/php/Forms/GridField/GridFieldDetailFormTest/Person.php
index ce97268c0e6..2717fed2019 100644
--- a/tests/php/Forms/GridField/GridFieldDetailFormTest/Person.php
+++ b/tests/php/Forms/GridField/GridFieldDetailFormTest/Person.php
@@ -5,6 +5,7 @@
 use SilverStripe\Dev\TestOnly;
 use SilverStripe\Forms\GridField\GridField;
 use SilverStripe\Forms\GridField\GridFieldConfig_RelationEditor;
+use SilverStripe\Forms\Validation\CompositeValidator;
 use SilverStripe\Forms\Validation\RequiredFieldsValidator;
 use SilverStripe\ORM\DataObject;
 use SilverStripe\ORM\DataObjectSchema;
@@ -65,14 +66,16 @@ public function getCMSFields()
         return $fields;
     }
 
-    public function getCMSValidator()
+    public function getCMSCompositeValidator(): CompositeValidator
     {
-        return new RequiredFieldsValidator(
+        $validator = parent::getCMSCompositeValidator();
+        $validator->addValidator(new RequiredFieldsValidator(
             [
             'FirstName',
             'Surname'
             ]
-        );
+        ));
+        return $validator;
     }
 
     public function getCMSEditLink(): ?string
diff --git a/tests/php/i18n/i18nTextCollectorTest.php b/tests/php/i18n/i18nTextCollectorTest.php
index 5c96f1e6637..ca30c10713c 100644
--- a/tests/php/i18n/i18nTextCollectorTest.php
+++ b/tests/php/i18n/i18nTextCollectorTest.php
@@ -83,7 +83,7 @@ public function testCollectFromNewTemplateSyntaxUsingParserSubclass()
         $mymodule = ModuleLoader::inst()->getManifest()->getModule('i18ntestmodule');
 
         $html = <<<SS
-        <% _t('Test.SINGLEQUOTE','Single Quote'); %>
+        <%t Test.SINGLEQUOTE 'Single Quote' %>
 <%t i18nTestModule.NEWMETHODSIG "New _t method signature test" %>
 <%t i18nTestModule.INJECTIONS_0 "Hello {name} {greeting}, and {goodbye}" name="Mark" greeting="welcome" goodbye="bye" %>
 <%t i18nTestModule.INJECTIONS_1 "Hello {name} {greeting}, and {goodbye}" name="Paul" greeting="welcome" goodbye="cya" %>