I have created two files. post.php and post-form.php. Both are in the widgets folder.
When I add the widget I created to an area, on the front end, I get the following error:
Warning: include(/wp-content/plugins/extreme-items/parts//wp-content/plugins/extreme-items/parts/widgets//post.php): failed to open stream: No such file or directory in /wp-content/plugins/piklist/includes/class-piklist.php on line 382
Looks like there are a few double / which might be the problem.