Widget Section Does Not Load Valid Blocks, "Legacy Widget" appears broken

Hello, first time poster so I apologize if this is formatted improperly.

The following happened after a recent update.

Upon entering the Widgets section, the following errors are repeatedly thrown:

The "nav_menu" block was affected by errors and may not function properly. Check the developer tools for more details.

The "icl_lang_sel_widget" block was affected by errors and may not function properly. Check the developer tools for more details.

Now, when developer tools are checked, they show an invalid JSON. Looking at the widgets themselves, they never load, just a spinning circle attempting to load.

They are being identified as "Legacy Widget"s by Wordpress.

When attempting to replace the “Navigation Menu” widget by searching for ‘menu’ blocks, all I see is “Navigation Menu”, the same invalid widget. What does not seem to appear as a valid selection is the “Navigation” block, which appears when attempting to edit a Page.

The other affected widget is a “Language Switcher” legacy widget. It also does not load in the widgets section, but I do not know of a block that could replace it either.

Though they appear invalid in the Widget section, all of them are still functional on the live website. I do not know what will happen if I attempt to change the widget section.

I’m uncertain as to why the Widget area is not loading the appropriate blocks, nor how to fix it. Does anyone have any feedback on this? Thank you!