Sometimes, duplicating an asset throws exception:

fo.magnolia.ui.contentapp.browser.BrowserPresenter: An error occurred while executing action [createVariant]
info.magnolia.ui.api.action.ActionExecutionException: Can't execute repository operation.
property /coop-pronto-52/mgnl:lastModified: the property cannot be saved because it has been modified externally.
at info.magnolia.ui.framework.action.AbstractRepositoryAction.execute(AbstractRepositoryAction.java:104)

Caused by: javax.jcr.InvalidItemStateException: property /coop-pronto-52/mgnl:lastModified: the property cannot be saved because it has been modified externally.

A visible error banner is displayed.

This happens:

• usually - sometimes it does not, not sure why.
• always happens on asset that ive just uploaded.

Note: Ive confirmed that this was working fine in 5.1 EE