TypeError when importing blocks if no blocks exported

If no blocks have been exported and you try to import blocks, the following error occurs:

[error] TypeError: count(): Argument #1 ($value) must be of type Countable|array, null given in count() (line 348 of /var/www/html/web/modules/contrib/structure_sync/src/Controller/BlocksController.php) #0 /var/www/html/web/modules/contrib/structure_sync/src/Controller/BlocksController.php(348): count()

#1 /var/www/html/web/modules/contrib/structure_sync/src/Controller/BlocksController.php(159): Drupal\structure_sync\Controller\BlocksController::importBlocksSafe()