General Support: Error message when attempting to import photos

I have some test photos (.jpgs) uploaded into the /uploads/ directory. When I try to import them, I get this error message:

Failed: $AvailableImageOutputFormats = array(text;wbmp;gif;png;jpeg) in file "phpthumb.class.php" on line 519 $this->thumbnailFormat set to $this->config_output_format "jpeg" in file "phpthumb.class.php" on line 529 $this->thumbnailFormat staying as "jpeg" because "" ($this->f) is not in $AvailableImageOutputFormats in file "phpthumb.class.php" on line 539 $this->thumbnailQuality set to "75" in file "phpthumb.class.php" on line 546 $this->config_cache_directory () is not a directory in file "phpthumb.class.php" on line 587 SetCacheFilename() failed because $this->config_cache_directory is empty in file "phpthumb.class.php" on line 1815 GetImageSize("") failed in file "phpthumb.class.php" on line 1800 starting SourceImageToGD() in file "phpthumb.class.php" on line 1886 Not using EXIF thumbnail data because $this->config_use_exif_thumbnail_for_speed is FALSE in file "phpthumb.class.php" on line 1889 phpThumb() v1.6.0-200507180958 "/usr/local/psa/home/vhosts/exitgravity.org/web_users/blog/plogger/uploads/sample.jpg" does not exist

..what does that mean? How do I fix it?