FULL PRODUCT VERSION :
java version "1.8.0_71"
Java(TM) SE Runtime Environment (build 1.8.0_71-b15)
Java HotSpot(TM) 64-Bit Server VM (build 25.71-b15, mixed mode)


A DESCRIPTION OF THE PROBLEM :
javax/imageio/ImageIO.java contains the following code:

    private static <S extends ImageReaderWriterSpi>
        String[] getReaderWriterInfo(Class<S> spiClass, SpiInfo spiInfo)
    {
        // Ensure category is present
        Iterator<S> iter;
        try {
            iter = theRegistry.getServiceProviders(spiClass, true);
        } catch (IllegalArgumentException e) {
            return new String[0];
        }

        HashSet<String> s = new HashSet<String>();
        while (iter.hasNext()) {
            ImageReaderWriterSpi spi = iter.next();
            Collections.addAll(s, spiInfo.info(spi));
        }

        return s.toArray(new String[s.size()]);
    }

This method here:

            Collections.addAll(s, spiInfo.info(spi));

Ultimately delegates to getMIMETypes():

        MIME_TYPES {
            @Override
            String[] info(ImageReaderWriterSpi spi) {
                return spi.getMIMETypes();
            }
        },

getMIMETypes() is clearly documented as potentially returning null, and the implementation clearly can, and does:

    /**
     ---- omitting ----
     * @return an array of <code>String</code>s or length at least 1
     * containing MIME types associated with this reader or writer, or
     * <code>null</code>.
     */
    public String[] getMIMETypes() {
        return MIMETypes == null ? null : (String[])MIMETypes.clone();
    }

So all you need is one provider in the classpath which has no MIME types defined, which isn't very hard to come by.

This failure to detect the null then triggers a NullPointerException from allAll:

    Caused by: java.lang.NullPointerException
     at java.util.Collections.addAll(Collections.java:5400)
     at javax.imageio.ImageIO.getReaderWriterInfo(ImageIO.java:468)
     at javax.imageio.ImageIO.getReaderMIMETypes(ImageIO.java:496)



ERROR MESSAGES/STACK TRACES THAT OCCUR :
    Caused by: java.lang.NullPointerException
     at java.util.Collections.addAll(Collections.java:5400)
     at javax.imageio.ImageIO.getReaderWriterInfo(ImageIO.java:468)
     at javax.imageio.ImageIO.getReaderMIMETypes(ImageIO.java:496)


REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
Workaround is presumably to avoid calling ImageIO.getReaderMIMETypes() and similar methods and implement the same iteration correctly in the client code.