I upgraded Magento 2 to Magento 2.0.3 today, everything went fine until I didn't get my webshop to work anymore with a lot of blank pages. Now I managed to get my pages to see errors again with the permissions set 644, 755 and var + pub + static folders are 777. Now that said I still get an error which is located in the lib/cache route here is the error:

a:4:{i:0;s:282:"Warning: file_put_contents(var/cache//mage-tags/mage---f56_CONFIG): failed to open stream: Permission denied in lib/internal/Cm/Cache/Backend/File.php on line 661";i:1;s:9007:"
#0 [internal function]: Magento\Framework\App\ErrorHandler->handler(2, 'file_put_conten...', '/home/smartphon...', 661, Array)
#1 lib/internal/Cm/Cache/Backend/File.php(661): file_put_contents('/home/smartphon...', 'f56_FRONTEND__R...', 10)
#2 lib/internal/Cm/Cache/Backend/File.php(174): Cm_Cache_Backend_File->_updateIdsTags(Array, Array, 'merge')
#3 vendor/magento/zendframework1/library/Zend/Cache/Core.php(390): Cm_Cache_Backend_File->save('a:0:{}', 'f56_FRONTEND__R...', Array, NULL)

It seems file.php can't write still while I changed every permission with permission owner and be on. I have no clue on what to do next. I cannot find it anywhere on the internet and never asked a question before so, here we go. Let's see if someone else manage to help me with this error.

  • Did one clean the cache? :D Mar 31, 2016 at 18:37
  • There was some issue with the 2.0.3 patch; we're working on 2.0.4 right now. Mar 31, 2016 at 22:28
  • @ Aivis: Yes i not only cleaned it, i deleted the var folder to let it be rebuild by the magento core.
    – Remy
    Apr 1, 2016 at 8:43
  • @SteveJohnson: Oh if this is the case that could be the problem. I'l wait for the next update then and reverse my current then
    – Remy
    Apr 1, 2016 at 8:43
  • @remy 2.0.4 is available now. You can try it anytime. Apr 2, 2016 at 14:37

3 Answers 3


I got the same error just 20 minutes back from now. I had changed "var" folder permission to 777 and all files to 644 within this folder, after that i got that error. I tried changing the folder permission again but failed.

So i just deleted "var" folder/directory and replaced with the "var" folder only .htaccess file within it. And it worked for me.

  • Again i received same error, but this time removing everything under "var" directory except .htaccess files worked for me. Jun 21, 2016 at 2:44

I read that Fast-CGI requires different permissions (755,644), than those that Magento uses by default (775,660).

You can try changing all permissions by using following command

find . -type d -exec chmod 755 {} \; && find . -type f -exec chmod 644 {} \;

and changing permissions Magento will use in future, by editing


I know it's not the prettiest solutions, but it worked for me.


If you set the permissions correctly, you could try below solution, it worked for me.

cd <your Magento install dir>
php bin/magento cache:flush

It seems old cache caused the problem, so what you need is to flush the cache.

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