Try instance relative path for wsgi.py first

wsgi.py

@@ -5,7 +5,7 @@ from flaskbb.utils.helpers import ReverseProxyPathFix
 _basepath = os.path.dirname(os.path.abspath(__file__))
 
 # will throw an error if the config doesn't exist
-flaskbb = create_app(config=os.path.join(_basepath, 'flaskbb.cfg'))
+flaskbb = create_app(config='flaskbb.cfg')
 
 #  Uncomment to use the middleware
 #flaskbb.wsgi_app = ReverseProxyPathFix(flaskbb.wsgi_app)