User Submitted Posts – Enable Users to Submit Posts from the Front End

Make sure that the setting "Images Auto-Display" is enabled
And/or make sure that the setting "Featured Image" is enabled
And/or make sure that your theme is set up to display submitted images

Assuming that everything is set up to display submitted images, here are some further things to check:

Is there any error message when trying to submit an image?
Check that the submitted images are uploaded to the Media Library
Check that the URL of the submitted image is attached to the submitted post as a Custom Field (on Edit Post screen)
Check the permission settings on the upload folder(s) by ensuring that you can successfully upload image files directly via the Media Uploader
Double-check that all the "Image Uploads" settings make sense, and that the images being uploaded meet the specified requirements

Note: when changing permissions on files and folders, it is important to use the least-restrictive settings possible. If you have to use more permissive settings, it is important to secure the directory against malicious activity. For more information check out: Secure Media Uploads
How to set submitted image as the featured image?
Here are the steps:

Visit USP settings > Options panel > Image Uploads > Featured Image
Check the box and click "Save Settings" to save your changes

Note that this setting merely assigns the submitted image as the Featured Image; it's up to your theme's single.php file to include the_post_thumbnail() to display the Featured Images. If your theme is not so equipped, check out this tutorial at WP-Mix.
How to require login?
Visit the plugin settings and enable the option to "Require User Login". That will display the submission form only to logged-in users. To go further and require login for other types of content, there are many techniques available to you. For more information check out my WP-Mix post, WordPress Require User Login, which provides a good summary of the possibilities. Also note: USP Pro includes built-in shortcodes to display forms and other content to registered/logged-in users and/or guests/logged-out users.
How do I change the appearance of the submission form?
The easiest way to customize the form is via the plugin settings. There you can choose one of the following form configurations:

HTML5 Form + Default CSS (Recommended)
HTML5 Form + Disable CSS (Provide your own styles)
Custom Form + Custom CSS (Provide your own form template & styles)

Additionally, you can configure the settings to show/hide specific fields, control the number and size of submitted images, customize the Challenge Question, and much more.

To go beyond what's possible with the plugin settings, USP enables creation of a custom submission form. To learn how, check out the "Custom Submission Form" section under Installation. And for advanced customization, developers can use USP action and filter hooks.

Or, to go further with unlimited custom forms, check out USP Pro :)
What is the "alternate" form?
Inside of the /views/ directory, you will find an alternate form template named submission-form-alt.php. This template is identical to that used for the default form, with the exception that it returns the post-submit form in addition to the success message. You can use the alternate form template by following the steps provided via the "Custom Submission Form" section of the plugin documentation/readme.
What about security and spam?
User Submitted Posts uses the WordPress API to keep everything secure, fast, and flexible. The plugin also features Google reCAPTCHA, Challenge Question, and hidden anti-spam field to stop automated spam and bad bots.
Can I include video?
The free version of USP supports uploads of images only, but some hosted videos may be included in the submitted content (textarea) by simply including the video URL on its own line. See this page for more info. Note that USP Pro enables users to upload video and much more.
How do I reset the plugin settings?
To reset plugin settings to factory defaults:

Visit "Restore Default Options" in the plugin settings
Check the box and save your changes
Deactivate the plugin and then reactivate it
Plugin settings now are restored to defaults

Restoring default settings does not delete any submitted posts. Even if you completely remove the plugin, the submitted posts will not be deleted. You have to remove them manually, if desired.
How do I enable the "Add Media" button for all users?
Question: How do I enable the "Add Media" button for all users (even if not registered)?

Answer: Users must have sufficient capabilities to access the Media Library and the "Add Media" button. This is a security measure aimed at preventing foul play. The Pro version of USP provides an option to enable Add Media uploads for all user levels.
Can you explain the setting "Registered Username"?
When "Registered Username" is enabled:

If the user is logged in, their registered username is used as the Post Author
If the user is logged out, the setting "Assigned Author" is used as the Post Author

The setting "Assigned Author" always is used as the Post Author for all users (whether logged in or not)

How can I translate this plugin?
Currently the easiest and most flexible method is to use GlotPress to translate USP. That is the recommended translation route going forward, but for the time being you may also translate using a plugin such as Loco Translate. FYI, USP's translation files are located in the /languages/ directory.
Why am I not receiving the Email Alerts?
Normally the plugin sends an Email Alert each time a post is submitted. If that is not happening in your case, you will need to troubleshoot your setup. Here is a guide on Troubleshooting Email that should help.
How to disable image preview feature?
To disable the image-preview thumbnail feature, add the following line to the plugin setting, "Custom Content":

<script>var usp_disable_previews = true;</script>

Save changes and done.
How to disable fancy category/tag select script?
USP uses the Chosen.js library to enhance the behavior and appearance of the Category and Tag fields. The enhanced fields will be displayed when either/both of the following are true:

The option "Multiple Categories" is enabled (for Category field)
The option "Use Existing Tags" is enabled (for Tag field)

If you want to disable the fancy Chosen script for these fields, you can do so by adding the following code snippet to your WordPress site:

<script>var usp_disable_chosen = true;</script>

Save changes and done. Also just FYI, here is a guide that explains how to add custom code to WordPress.
How to change the language for Google reCaptcha?
By default, the Google reCaptcha field is displayed in English. To change that to some other language, first locate the two-digit abbreviation for your language here. Then add the following code to your theme (or child theme) functions.php, or add via custom plugin:

function usp_recaptcha_querystring($query) { return 'en'; }
add_filter('usp_recaptcha_querystring', 'usp_recaptcha_querystring');

Notice where it says en, that is the two-character language code you want to replace with your own. Then save changes and done.
Where can I check out a demo of the USP form?
There is a simplified USP Demo at Perishable Press. Note the demo form is non-functional, just there to give you a general idea. The actual form provided by the plugin has more features, functionality, etc.
How to allow blank targets in post content?
By default, USP removes any target="_blank" attributes in submitted post content. This is a recommended security feature. It is possible however to allow blank targets:

function usp_content_patterns($array) { return array(); }
add_filter('usp_content_patterns', 'usp_content_patterns');

That code can be added via theme (or child theme) functions.php, or add via custom plugin.
How to disable all HTML tags in submitted posts?
Add the code snippet provided here.
How does the remote delete post link work?
When %%delete_link%% is included in your email alert template, a link will be included that the user can click to delete their submitted post. This works when the user who submitted the post is logged in to WordPress. It does not work for users who are not logged in, or are not the post author. For more details and tips, check out the USP FAQs at Perishable Press.
How to remove placeholder text on submission form?
You can either enable the custom form and modify the output/HTML directly, or you can just add the following to the plugin's "Custom Content" option:

<script>jQuery(document).ready(function($) {
$('.usp-title label').text('This is the label');
$('.usp-title input').attr('placeholder', 'This is the placeholder');
});</script>

Change the two text strings, "This is the label" and "This is the placeholder" to whatever you would like. Then save changes and done.
More FAQs
Want to read some more FAQs? Check out the USP FAQs at Perishable Press
Questions? Feedback?
Send any questions or feedback via my contact form. Thanks! :)