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.
Best Answer
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.