I can't upload to Media Library??

I get the same problem!

nguienu Are using some type of plugin for media? Where is the dotted line box coming from?

I tried “WordPress Flash Uploader” plugin, it just has Error 500:
https://i.lulzimg.com/90209bee9f.jpg

Disable all plugins. Switch to the twentyeleven theme.

Is this resolved?

I can’t upload files >100KB, it notices error 500 again.

My Maximum upload file size: 2MB

I don’t know this error for WP 3.3 or my VPS. because that previous time I upgraded from shared hosting to VPS, then I upgraded WP 3.2.1 to WP 3.3. I contacted to my hosting provider, they said that: Error by WordPress 3.3 ?? what should I do??

I disabled all plugins. Switch to the Twentyeleven theme as you said, but it just notices Error 500:

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, [no address given] and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Apache/2.2.16 (Debian) Server at mywebsite.com Port 80

I’m sure that I can upload the files < 100KB. files > 100KB it errors.