warning: Invalid argument supplied for foreach()

When i first visit the website I'm working on I get this error message at the top of the page, sometimes it's listed once, sometimes twice and up to 10-20 times.

If I hit refresh or visit another page the error disappears. What would cause this?

warning: Invalid argument supplied for foreach() in /home/sitename/public_html/modules/taxonomy/taxonomy.module on line 1453.

This has occurred after upgrading from 5.6 to 5.7. During the upgrade I had one major issue - I somehow lost two Nodes (displayed contents of "N/A") which I restored from backup DB to the node_revisions table.