• Lets say, you want to upload 500 pictures to a category CALIFORNIA. Now goto images/phocagallery and create a folder, named "CALIFORNIA" . Now, inside it, create around 50 sub folders and name them as follows, "BATCH 1 , BATCH 2 , BATCH 3 , BATCH 4 , BATCH 5....... BATCH 49, BATCH 50"
• Since you have 500 pictures, upload 10 pictures per folder . I mean, 10 pictures in BATCH 1 folder, next 10 pictures in BATCH 2 folder, ........ till Batch 50 folder.
• Now goto the PhocaGallery Backend and goto its IMAGES tab. Now click on MULTIPLE ADD . On the next page, click on CALIFORNIA folder, which you had created in the FTP and then click on BATCH 1 . When you click on BATCH 1, it will show you the 10 pictures, which you had uploaded on that folder via FTP. Just select those 10 pictures and select CALIFORNIA from the drop down selector of IMAGE CATEGORIES and press SAVE.
• Images are saved. Now, just select CALIFORNIA from the drop down of Image Categories in the IMAGES tab, so that those 10 thumbnails are created first. This is an important step , because, if you dont open the category afetr every batch folder's multiple addition of images, then they wont create their thumbnails and atlast wil again 500 Internal Server Error, when you click it at last.

So, the theory is lets do 10-10 pics uploading and let it create its thumbnails . Since we are not doing 100-200 pictures at a time, so there wont be any internal server error now. Let me know, if you got my idea.. Its the last possible solution now. So, if you still have problems with it, then post it at our forums.