не работает phpThumbOf

edit phpThumb.config.php and (temporarily) set
$PHPTHUMB_CONFIG['disable_debug'] = false;
to view the details of this error in file "phpthumb.class.php" on line 4126
    [34] => SourceImageToGD() failed in file "phpthumb.class.php" on line 374
)

[2017-02-17 16:37:20] (ERROR @ /var/www/vhosts/domain/centrvet-modx/core/components/phpthumbof/model/phpthumbof/phpthumbof.class.php : 379) [phpThumbOf] Could not generate thumbnail: assets/img/doctors/1486043970.jpg - Debug: Array
(
    [0] => phpThumb() v1.7.14-201608101311 in file "phpthumb.class.php" on line 229
    [1] => setCacheDirectory() starting with config_cache_directory = "/var/www/vhosts/domain/centrvet-modx/core/cache/phpthumb/" in file "phpthumb.class.php" on line 1005
    [2] => setting config_cache_directory to $this->realPathSafe(/var/www/vhosts/domain/centrvet-modx/core/cache/phpthumb) = "/var/www/vhosts/domain/centrvet-modx/core/cache/phpthumb" in file "phpthumb.class.php" on line 1033
    [3] => setCacheDirectory() starting with config_cache_directory = "/var/www/vhosts/domain/centrvet-modx/assets/components/phpthumbof/cache/" in file "phpthumb.class.php" on line 1005
    [4] => setting config_cache_directory to $this->realPathSafe(/var/www/vhosts/domain/centrvet-modx/assets/components/phpthumbof/cache) = "/var/www/vhosts/domain/centrvet-modx/assets/components/phpthumbof/cache" in file "phpthumb.class.php" on line 1033
    [5] => setSourceFilename(assets/img/doctors/1486043970.jpg) set $this->sourceFilename to "assets/img/doctors/1486043970.jpg" in file "phpthumb.class.php" on line 294
    [6] => CleanUpCacheDirectory() set to purge (30.0 days; 100.00 MB; 10,000 files) in file "phpthumb.class.php" on line 712
    [7] => CleanUpCacheDirectory() skipped because "/var/www/vhosts/domain/centrvet-modx/assets/components/phpthumbof/cache/phpThumbCacheStats.txt" is recently modified in file "phpthumb.class.php" on line 722
    [8] => $AvailableImageOutputFormats = array(text;ico;bmp;wbmp;gif;png;jpeg) in file "phpthumb.class.php" on line 969
    [9] => $this->thumbnailFormat set to $this->config_output_format "jpeg" in file "phpthumb.class.php" on line 980
    [10] => $this->thumbnailFormat set to $this->f "jpeg" in file "phpthumb.class.php" on line 987
    [11] => $this->thumbnailQuality set to "75" in file "phpthumb.class.php" on line 997
    [12] => $this->sourceFilename set to "/var/www/vhosts/domain/centrvet-modx/centrvet-modx/assets/img/doctors/1486043970.jpg" in file "phpthumb.class.php" on line 894
    [13] => phpThumb() v1.7.14-201608101311
http://phpthumb.sourceforge.net

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