diff --git a/backup/util/loggers/file_logger.class.php b/backup/util/loggers/file_logger.class.php
index 98ff74acf39..97ae661339a 100644
--- a/backup/util/loggers/file_logger.class.php
+++ b/backup/util/loggers/file_logger.class.php
@@ -50,11 +50,18 @@ class file_logger extends base_logger {
     }
 
     public function __destruct() {
-        @fclose($this->fhandle); // Blindy close the file handler (no exceptions in destruct)
+        if (is_resource($this->fhandle)) {
+            // Blindy close the file handler (no exceptions in destruct).
+            @fclose($this->fhandle);
+        }
     }
 
     public function __sleep() {
-        @fclose($this->fhandle); // Blindy close the file handler before serialization
+        if (is_resource($this->fhandle)) {
+            // Blindy close the file handler before serialization.
+            @fclose($this->fhandle);
+            $this->fhandle = null;
+        }
         return array('level', 'showdate', 'showlevel', 'next', 'fullpath');
     }
 
@@ -90,7 +97,7 @@ class file_logger extends base_logger {
         } else {
             $content = $prefix . str_repeat('&nbsp;&nbsp;', $depth) . htmlentities($message, ENT_QUOTES, 'UTF-8') . '<br/>' . PHP_EOL;
         }
-        if (false === fwrite($this->fhandle, $content)) {
+        if (!is_resource($this->fhandle) || (false === fwrite($this->fhandle, $content))) {
             throw new base_logger_exception('error_writing_file', $this->fullpath);
         }
         return true;
diff --git a/cache/stores/file/lib.php b/cache/stores/file/lib.php
index dd5e05825e4..0c08710d551 100644
--- a/cache/stores/file/lib.php
+++ b/cache/stores/file/lib.php
@@ -399,7 +399,7 @@ class cachestore_file extends cache_store implements cache_is_key_aware, cache_i
     public function delete($key) {
         $filename = $key.'.cache';
         $file = $this->file_path_for_key($key);
-        if (@unlink($file)) {
+        if (file_exists($file) && @unlink($file)) {
             unset($this->keys[$filename]);
             return true;
         }
diff --git a/lib/classes/task/file_temp_cleanup_task.php b/lib/classes/task/file_temp_cleanup_task.php
index 05bfd5cccbd..d4971dc84d3 100644
--- a/lib/classes/task/file_temp_cleanup_task.php
+++ b/lib/classes/task/file_temp_cleanup_task.php
@@ -90,7 +90,11 @@ class file_temp_cleanup_task extends scheduled_task {
             } else {
                 // Return the time modified to the original date only for real files.
                 if ($iter->isDir() && !$iter->isDot()) {
-                    touch($node, $modifieddateobject[$node]);
+                    try {
+                        @touch($node, $modifieddateobject[$node]);
+                    } catch (\Throwable $t) {
+                        null;
+                    }
                 }
             }
         }
diff --git a/lib/filestorage/file_system_filedir.php b/lib/filestorage/file_system_filedir.php
index 103dcca41e5..8c26da3b6dd 100644
--- a/lib/filestorage/file_system_filedir.php
+++ b/lib/filestorage/file_system_filedir.php
@@ -378,7 +378,9 @@ class file_system_filedir extends file_system {
         // Let's try to prevent some race conditions.
 
         $prev = ignore_user_abort(true);
-        @unlink($hashfile.'.tmp');
+        if (file_exists($hashfile.'.tmp')) {
+            @unlink($hashfile.'.tmp');
+        }
         if (!copy($pathname, $hashfile.'.tmp')) {
             // Borked permissions or out of disk space.
             @unlink($hashfile.'.tmp');
@@ -393,7 +395,10 @@ class file_system_filedir extends file_system {
         }
         rename($hashfile.'.tmp', $hashfile);
         chmod($hashfile, $this->filepermissions); // Fix permissions if needed.
-        @unlink($hashfile.'.tmp'); // Just in case anything fails in a weird way.
+        if (file_exists($hashfile.'.tmp')) {
+            // Just in case anything fails in a weird way.
+            @unlink($hashfile.'.tmp');
+        }
         ignore_user_abort($prev);
 
         return array($contenthash, $filesize, $newfile);
@@ -467,7 +472,10 @@ class file_system_filedir extends file_system {
         }
         rename($hashfile.'.tmp', $hashfile);
         chmod($hashfile, $this->filepermissions); // Fix permissions if needed.
-        @unlink($hashfile.'.tmp'); // Just in case anything fails in a weird way.
+        if (file_exists($hashfile.'.tmp')) {
+            // Just in case anything fails in a weird way.
+            @unlink($hashfile.'.tmp');
+        }
         ignore_user_abort($prev);
 
         return array($contenthash, $filesize, $newfile);