undefined function json_decode

solved 

Solved, but how?

@George Did you encounter the same issue? Is File | Settings | Languages & Frameworks | PHP > PHP Runtime > Bundled > json enabled?

Thanks for the help/hint. I got the same in PhPStorrm. Fixed with:

1. Menu: File / Settings / PHP / Tab: PHP Runtime / Button:  Sync Extensions with Interpreter
2. Menu: File / "Invalidate Caches / Restart..."

It's strange that json_decode() started showing up as unknown this morning. All I did was get the bash update.

My PHPStorm has smae problem started today sfter update from 2020.1 to 2020.2.

I tried your step but not help. And it looks PHPStorm lost references to all php extensions.

@Standus

Please check https://youtrack.jetbrains.com/issue/WI-54626 -- you may need to delete caches folders manually (when IDE is closed)

I found what is the problem. After disable plugin "PHP Document 1.1" https://github.com/fw6669998/php-doc then its OK.