Exception on drag and drop

[onlyafly]

Expected behaviour

When I drag a PNG image from Finder onto the assets view, the image is added to the project.

Actual behaviour

I get an "java.lang.UnsupportedOperationException: Flush is forbidden from target!" error and the image is not added.

Steps to reproduce

1. Try dragging a PNG file from Finder onto the Assets panel (not directly onto a sub-folder)
2. Error occurs.

---

Build time	2018-04-04T10:27:19.326624
Defold channel	editor-alpha
Defold editor sha	05f53bc54bbb73befbb40580acb38dfc711fff90
Defold engine sha	e3f2a48e6495946eb8aede3c843471bb037976aa
Defold version	1.2.124
Error	cac8fc9276464d52a1ebdcb8b78056b7
GPU	AMD Radeon Pro 560 OpenGL Engine
GPU Driver	2.1 ATI-1.60.26
Java version	1.8.0_102-b14
OS arch	x86_64
OS name	Mac OS X
OS version	10.13.3

[matgis-king]

Duplicate of #1743.

[AGulev]

I can't reproduce this issue in 1.2.144.

[matgis-king]

Me neither. I believe this is quite rare, but can still happen. If I remember correctly, there was a JDK bug that was causing it. Once we update the JDK, I guess we'll be able to see if it still happens to some users.