Em Dee

The upgrade has broken my site. I'm no techie, so have no idea what most of you are talking about and hoping Support can log in remotely soon and sort it out for me. I don't have a local installation and usually just click the 'Upgrade' buttons and let the magic happen. Now getting error messages: CANNOT_WRITE /var/www/html/107811/system/File/Amazon.php::321 AND SignatureDoesNotMatch: The request signature we calculated does not match the signature you provided. Check your secret access key and signing method. IPS\File\Exception: CANNOT_WRITE (3) #0 /var/www/html/107811/system/File/File.php(366): IPS\File\_Amazon->save() #1 /var/www/html/107811/system/Theme/Theme.php(5576): IPS\_File::create('core_Theme', '341e4a57816af3b...', ' :root{--sp-0:0...', 'css_built_0', false, NULL, false) #2 /var/www/html/107811/system/Theme/Theme.php(2718): IPS\_Theme::writeCss(Array) #3 /var/www/html/107811/system/Theme/Theme.php(652): IPS\_Theme->compileCss('core', 'global', 'framework', 'framework.css') #4 /var/www/html/107811/system/Dispatcher/Standard.php(54): IPS\_Theme->css('framework.css', 'core', 'global') #5 /var/www/html/107811/system/Dispatcher/Admin.php(89): IPS\Dispatcher\_Standard::baseCss() #6 /var/www/html/107811/system/Dispatcher/Dispatcher.php(110): IPS\Dispatcher\_Admin->init() #7 /var/www/html/107811/admin/index.php(13): IPS\_Dispatcher::i() #8 {main}