Try re-indexing using the Magento 2 CLI
ssh into the server where your Magento files are and go into your Magento root folder.
cd /var/www/html/magento2
From that folder you can access the magento 2 cli with
bin/magento
If you can't start it, use chmod +x bin/magento
in order to re-index data via the CLI, use the following command
bin/magento indexer:reindex
If you want to be sure that NO cache is kept, you can remove the following folders from the var directory with:
rm -rf var/cache var/generation var/pagecache var/di
and then re-compile magento using command
bin/magento setup:di:compile
I hope this will help you.
