Warning message: Trying to access array offset on value of type bool

Problem/Motivation

When we get to the course summary page, we get a warning message about incorrect array usage:
Warning: Trying to access array offset on value of type bool in Drupal\opigno_learning_path\Progress->buildSummary() (line 437 of modules/contrib/opigno_learning_path/src/Progress.php).

Steps to reproduce

Сlear previous course results and go to the course page.

Proposed resolution

This message appears because the function that receives the results returns a boolean value. To correct the situation, check the variable before converting the string to a date. In place of line 437
'#complite_date' => strtotime($status["registered"]) ?? 0,
you need to change the following line
'#complite_date' => is_bool($status) ? 0 : strtotime($status["registered"]),