Uncaught Error: Call to a member function delete() on null

[greatestview]

Got this error message:

Ein Fehler vom Typ E_ERROR wurde in der Zeile 301 der Datei
[…]/wp-content/plugins/grid/lib/grid/classes/Endpoint.php
verursacht. Fehlermeldung: Uncaught Error: Call to a member function
delete() on null in
[…]/wp-content/plugins/grid/lib/grid/classes/Endpoint.php:301
Stack trace:
#0 [internal function]: Palasthotel\Grid\Endpoint->removeBox()
#1 (closed) […]/wp-content/plugins/grid/lib/grid/classes/API.php(118):
ReflectionMethod->invokeArgs()
#2 (closed) […]/wp-content/plugins/grid/classes/TheGrid.php(184):
Palasthotel\Grid\API->handleAjaxCall()
#3 (closed) […]/wp-includes/class-wp-hook.php(307):
Palasthotel\Grid\WordPress\TheGrid->ajax()
#4 (closed) […]/wp-includes/class-wp-hook.php(331):
WP_Hook->apply_filters()
#5 (closed) […]/wp-includes/plugin.php(474):
WP_Hook->do_action()
#6 (closed) […]/wp-admin/admin.php(259):
do_action()
#7 (closed) {main}
thrown

That is happening here:
https://github.com/palasthotel/grid/blob/74db6708401f42b1fffd6ea9053db8b33524fca7/classes/Endpoint.php#L295C1-L303

                                                $box=null;
                                                if(isset($slot->boxes[$idx]))
                                                        $box=$slot->boxes[$idx];
                                                $ret=$slot->removeBox($idx);
                                                if($ret)
                                                {
                                                        $box->delete();
                                                }
                                                return $ret;

$box is set to null, so it’s quite obvious this error could be thrown. $box->delete(); should only be called, if $box is set. I don’t know about the details of this file and code snippet, so I cannot provide a pull request.