EDIT

In Flora of Greece I tried to move an image from taxon Anchusa aegyptiaca to Anchusella variegata.
I did this by first adding the image also to Anchusella variegata, later I wanted to remove it from Anchusa aegyptiaca.

However, as long as Anchusa aegyptiaca was also opened in separate name editor the below exception was thrown reproducable (I reopened Anchusella variegata a couple of times).

After closing Anchusa aegyptiaca it was possible to add the image to Anchusella variegata and save).

==> hmm, no, even then it did not work. I closed all other editors and the problem still remained. Only after restarting the TaxEditor the problem disappeared. So it looks like the TaxEditor under certain conditions remembers something that leads to multiple representation exceptions!!!

login : admin
editor version : 5.5.1
server : api.cybertaxonomy.org (cybertaxonomy.org) / flora-greece
schema version : 5.0.0.0.20180514
os : Windows Server 2012 R2 6.3 amd64
java : 1.8.0_121
org.eclipse.e4.core.di.InjectionException: java.lang.IllegalStateException: Multiple representations of the same entity [eu.etaxonomy.cdm.model.media.Media#4495] are being merged. Detached: [Anchusa aegyptiaca (L.) A. DC. (Willing 4)]; Detached: [Anchusa aegyptiaca (L.) A. DC. (Willing 4)]
    at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:65)
    at org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:282)
    at org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:247)
    at org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(ContextInjectionFactory.java:90)
    at org.eclipse.e4.ui.internal.workbench.PartServiceSaveHandler.save(PartServiceSaveHandler.java:57)
    at org.eclipse.ui.internal.WorkbenchWindow$7.save(WorkbenchWindow.java:594)
    at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.savePart(PartServiceImpl.java:1390)
    at eu.etaxonomy.taxeditor.workbench.SaveHandler.execute(SaveHandler.java:36)
    at sun.reflect.GeneratedMethodAccessor158.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:55)
    at org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:282)
    at org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:264)