Hi,
Many of the wordpress users are receiving this kind of error message while performing the wordpress upgrade. To overcome of this problem please refer these steps:
1. Try to upgrade via Tools->Upgrade->Re-install automatically.
2. If that fails then disable all plugins and perform a manual upgrade.
Thanks,
Shane G.
Popularity: 1%
I only just noticed this error message on one of my pages. Following your instr. I got rid of the error. Thanks for help!