First of all, try to do the following:
Please ensure that your IDE is up to date (except Android Studio; details in this article).
Ensure that you have the Hyperskill Academy plugin installed and up to date.
To update your IDE to the latest version, on the welcome screen, please click on the Gear Icon > Check for Updates... and install all available updates.
Log out from your Hyperskill account and log in back in Settings/Preferences > Tools > Hyperskill in IDE. Make sure that you are using the same profile in the IDE and at Hyperskill!
Remove the project from the Recent Projects view on the Welcome Screen.
Start a Hyperskill project by going to Hyperskill Academy from the Welcome screen, in the File menu by choosing File > Hyperskill Academy > Browse Courses, or select a project directly from the platform after selecting a course.
If the steps described above did not help, try exploring other articles in this section. If those do not resolve your issue, please refer to the article "What to do if I can't find a solution to my IDE problem."