Importing photos into an album

I have problems adding photos into albums. The photos are on the server and are not zipped. When I set the source directory and select the photos, it says that they are imported but when I go to the album the thumbnails aren’t there. When I go to another area it says database fixed, invalid entries removed.

I have 38 albums and this has only just started happening. 34 of them have imported without any issues but none of the remaining albums will import.

If I delete the photo from the album it says that the file and the thumbnail do not exist.

I have tried deleting the photos and uploading to the server again but this hasn’t made any difference. I have also tried deleting the plugin and re-installing from a fresh download. this hasn’t fixed it either.

If anyone has any ideas it would be appreciated.