Media uploads fine but gives 500 error in browser

Try deactivating all plugins. If that resolves the issue, reactivate each one individually until you find the cause.

If that does not resolve the issue, try switching to the Twenty Ten theme to rule-out a theme-specific issue.

Jame – thank you. It appears to be a theme-specific issue.

No – I spoke too soon. Reverted back to twenty-10, uploaded photo:

https://www.beyondthepasta.com/wp-content/uploads/elegant_masthead_image.jpg

Still 500 error. I suspect this is a web.config issue related to permalinks. Not using anything weird for permalink structure: /%year%/%monthnum%/%day%/%postname%/ – but client needs this structure.

web.config:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
<!-- <httpErrors existingResponse="Replace" errorMode="Detailed" />-->
        <defaultDocument>
            <files>
                <remove value="index.php" />
                <add value="index.php" />
            </files>
        </defaultDocument>

		<rewrite><rules><clear />
		<rule name="wordpress" patternSyntax="Wildcard">
					<match url="*" />
						<conditions>
							<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
							<add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
						</conditions>
					<action type="Rewrite" url="index.php" />
				</rule>

		</rules></rewrite>

    </system.webServer>
</configuration>

I found the issue – and the fix to this unbelievably annoying problem. WordPress needs to mention this in the setup for Windows servers… I spent 4 days tearing my hair out over this simple permissions issue with PHP and wp-admin/uploads.

See: https://www.howyoudo.info/index.php/how-to-fix-windows-server-upload-file-inherit-permissions-error/