“Trying to get property ‘current’ of non-object….”

Just downgraded from 5.7 to 5.6.2 via WP Downgrade. The site looks fine, but when I am in Updates, I see these errors. Please advise; thanks.

Notice: Trying to get property 'current' of non-object in /hermes/bosnacweb05/bosnacweb05aw/b2466/ipw.grapeheartnet/public_html/wp-admin/update-core.php on line 41

Notice: Trying to get property 'locale' of non-object in /hermes/bosnacweb05/bosnacweb05aw/b2466/ipw.grapeheartnet/public_html/wp-admin/update-core.php on line 41

Notice: Trying to get property 'locale' of non-object in /hermes/bosnacweb05/bosnacweb05aw/b2466/ipw.grapeheartnet/public_html/wp-admin/update-core.php on line 43

Notice: Trying to get property 'locale' of non-object in /hermes/bosnacweb05/bosnacweb05aw/b2466/ipw.grapeheartnet/public_html/wp-admin/update-core.php on line 45

Notice: Trying to get property 'response' of non-object in /hermes/bosnacweb05/bosnacweb05aw/b2466/ipw.grapeheartnet/public_html/wp-admin/update-core.php on line 64
If you need to re-install version –, you can do so here:

Notice: Trying to get property 'current' of non-object in /hermes/bosnacweb05/bosnacweb05aw/b2466/ipw.grapeheartnet/public_html/wp-admin/update-core.php on line 151

Notice: Trying to get property 'locale' of non-object in /hermes/bosnacweb05/bosnacweb05aw/b2466/ipw.grapeheartnet/public_html/wp-admin/update-core.php on line 152

Notice: Trying to get property 'locale' of non-object in /hermes/bosnacweb05/bosnacweb05aw/b2466/ipw.grapeheartnet/public_html/wp-admin/update-core.php on line 161

Notice: Trying to get property 'locale' of non-object in /hermes/bosnacweb05/bosnacweb05aw/b2466/ipw.grapeheartnet/public_html/wp-admin/update-core.php on line 170
This localized version contains both the translation and various other localization fixes.