In case you are getting this error during Magento 2 phrase collection:
In Phrase.php line 90:
Missed phrase
you can be sure there is at least one phrase empty in your code. Magento consides any __('') as empty phrase. You can find it by running:
grep -rnw -E -i "__\((""|'')\)" app/
from your Magento root directory. This will find all empty phrases in your code.
