Le script de génération de vignettes ne fonctionne pas

2019-07-10_12:33:20.316 [pool-4-thread-2] INFO  c.u.m.scheduler.GenerateThumbnailJob - Traitement du média "/medias/photo/img_1190651957059.jpg"
2019-07-10_12:33:20.316 [pool-4-thread-2] INFO  c.u.m.scheduler.GenerateThumbnailJob - Vignette détectée pour le média "/medias/photo/img_1190651957059.jpg". Récupération des informations.
2019-07-10_12:33:20.316 [pool-4-thread-2] INFO  c.u.m.scheduler.GenerateThumbnailJob - Création de la vignette pour le média "/medias/photo/img_1190651957059.jpg".
2019-07-10_12:33:20.316 [pool-4-thread-2] INFO  c.u.m.scheduler.GenerateThumbnailJob - Tentative de calcul des dimensions du média /medias/photo/img_1190651957059.jpg
2019-07-10_12:33:20.317 [pool-4-thread-2] INFO  c.u.m.scheduler.GenerateThumbnailJob - Préparation du redimmensionnement du média /medias/photo/img_1190651957059.jpg : dimension ciblée [150x150]
2019-07-10_12:33:20.321 [pool-4-thread-2] ERROR com.univ.utils.FileUtil - Erreur lors de l'ecriture du fichier /usr/local/ksup/www/storage/medias/photo
java.io.FileNotFoundException: /usr/local/ksup/www/storage/medias/photo (est un dossier)
	at java.io.FileOutputStream.open0(Native Method) ~[na:1.8.0_152]
	at java.io.FileOutputStream.open(FileOutputStream.java:270) ~[na:1.8.0_152]
	at java.io.FileOutputStream.<init>(FileOutputStream.java:213) ~[na:1.8.0_152]
	at java.io.FileOutputStream.<init>(FileOutputStream.java:162) ~[na:1.8.0_152]
	at com.univ.utils.FileUtil.primitiveCopierFichier(FileUtil.java:147) ~[core-6.05.33.jar:na]
	at com.univ.utils.FileUtil.copierFichier(FileUtil.java:126) ~[core-6.05.33.jar:na]
	at com.univ.mediatheque.scheduler.GenerateThumbnailJob.rebuildThumbnails(GenerateThumbnailJob.java:124) [core-6.05.33.jar:na]
	at com.univ.mediatheque.scheduler.GenerateThumbnailJob.perform(GenerateThumbnailJob.java:57) [core-6.05.33.jar:na]
	at com.kportal.scheduling.spring.quartz.LogReportJob.execute(LogReportJob.java:54) [core-6.05.33.jar:na]
	at org.quartz.core.JobRunShell.run(JobRunShell.java:202) [quartz-2.2.2.jar:na]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_152]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_152]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_152]

2019-07-10_12:33:20.322 [pool-4-thread-2] INFO  c.u.m.scheduler.GenerateThumbnailJob - Préparation du redimmensionnement du média /medias/photo/img_1190651989158.jpe : dimension ciblée [150x150]
2019-07-10_12:33:20.323 [pool-4-thread-2] ERROR org.quartz.core.JobRunShell - Job DEFAULT.thumbnailJob threw an unhandled Exception: 
java.util.NoSuchElementException: null
	at javax.imageio.spi.FilterIterator.next(ServiceRegistry.java:849) ~[na:1.8.0_152]
	at javax.imageio.ImageIO$ImageWriterIterator.next(ImageIO.java:842) ~[na:1.8.0_152]
	at javax.imageio.ImageIO$ImageWriterIterator.next(ImageIO.java:827) ~[na:1.8.0_152]
	at com.univ.utils.PhotoUtil.resize(PhotoUtil.java:71) ~[core-6.05.33.jar:na]
	at com.univ.mediatheque.scheduler.GenerateThumbnailJob.rebuildThumbnails(GenerateThumbnailJob.java:123) ~[core-6.05.33.jar:na]
	at com.univ.mediatheque.scheduler.GenerateThumbnailJob.perform(GenerateThumbnailJob.java:57) ~[core-6.05.33.jar:na]
	at com.kportal.scheduling.spring.quartz.LogReportJob.execute(LogReportJob.java:54) ~[core-6.05.33.jar:na]
	at org.quartz.core.JobRunShell.run(JobRunShell.java:202) ~[quartz-2.2.2.jar:na]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_152]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_152]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_152]
2019-07-10_12:33:20.323 [pool-4-thread-2] ERROR org.quartz.core.ErrorLogger - Job (DEFAULT.thumbnailJob threw an exception.
org.quartz.SchedulerException: Job threw an unhandled exception.
	at org.quartz.core.JobRunShell.run(JobRunShell.java:213) ~[quartz-2.2.2.jar:na]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_152]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_152]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_152]
Caused by: java.util.NoSuchElementException: null
	at javax.imageio.spi.FilterIterator.next(ServiceRegistry.java:849) ~[na:1.8.0_152]
	at javax.imageio.ImageIO$ImageWriterIterator.next(ImageIO.java:842) ~[na:1.8.0_152]
	at javax.imageio.ImageIO$ImageWriterIterator.next(ImageIO.java:827) ~[na:1.8.0_152]
	at com.univ.utils.PhotoUtil.resize(PhotoUtil.java:71) ~[core-6.05.33.jar:na]
	at com.univ.mediatheque.scheduler.GenerateThumbnailJob.rebuildThumbnails(GenerateThumbnailJob.java:123) ~[core-6.05.33.jar:na]
	at com.univ.mediatheque.scheduler.GenerateThumbnailJob.perform(GenerateThumbnailJob.java:57) ~[core-6.05.33.jar:na]
	at com.kportal.scheduling.spring.quartz.LogReportJob.execute(LogReportJob.java:54) ~[core-6.05.33.jar:na]
	at org.quartz.core.JobRunShell.run(JobRunShell.java:202) ~[quartz-2.2.2.jar:na]
	... 3 common frames omitted