http 500 internal server error?

[ApplianceJunk]

When I go to add a photo to the gallery pro I get the HTTP 500 Internal Server Error page.

The website cannot display the page
 HTTP 500 
   Most likely causes:
The website is under maintenance.
The website has a programming error.
 
   What you can try:
     Refresh the page.
 
     Go back to the previous page.
 
     More information
 

If I click "Refresh the page" it takes me back to my site, but I get a An Error Has Occurred! box that say's You need to enter a picture title.

I did add a title the first time I tried to add the photo.

After all the errors I go back to the gallery to see that the photo I had been trying to add does show up in the gallery.

I check the SMF admin error log, but it does not show any errors.

Why do I get taken to a HTTP 500 page like that?

Thanks,

[ApplianceJunk]

I do see errors in my log now.

AJ   Today at 06:06:42 PM 
 96.2.185.56     081b2582939760826ff354998591f44e 
 http://appliancejunk.com/forums/index.php?action=gallery&sa=add2 
8: Undefined index: userid
File: /home/applianc/public_html/forums/Sources/Gallery.php
Line: 1235
 
   AJ   Today at 06:06:42 PM 
 96.2.185.56     081b2582939760826ff354998591f44e 
 http://appliancejunk.com/forums/index.php?action=gallery&sa=add2 
8: Undefined index: cat
File: /home/applianc/public_html/forums/Sources/Gallery.php
Line: 1234
 
   AJ   Today at 06:06:42 PM 
 96.2.185.56     081b2582939760826ff354998591f44e 
 http://appliancejunk.com/forums/index.php?action=gallery&sa=add2 
8: Undefined index: keywords
File: /home/applianc/public_html/forums/Sources/Gallery.php
Line: 1233
 
   AJ   Today at 06:06:42 PM 
 96.2.185.56     081b2582939760826ff354998591f44e 
 http://appliancejunk.com/forums/index.php?action=gallery&sa=add2 
8: Undefined index: description
File: /home/applianc/public_html/forums/Sources/Gallery.php
Line: 1232
 
   AJ   Today at 06:06:42 PM 
 96.2.185.56     081b2582939760826ff354998591f44e 
 http://appliancejunk.com/forums/index.php?action=gallery&sa=add2 
8: Undefined index: title
File: /home/applianc/public_html/forums/Sources/Gallery.php
Line: 1231
 

[SMFHacks]

Could be either a permissions issue on the Gallery.php needs to be at least 755, the host can running out of space, or if it is large photo it may exceed php upload limits.

[ApplianceJunk]

gallery.php was set to 0644

I changed it to 775 and also tried 777, still get the http 500 page.

I tried it with very small photos and still get the http 500 page.

Cpanel shows I have lots of space, but before I check with my host could it be something else with the Sources/Gallery.php file?

I removed a couple mods a few day's ago. Removed them without any errors at the time, but now I wonder if removing other mods changed anything in the Sources/Gallery.php that could be causing this problem?