Dragger breaks when multiple files are selected and some are invalid

[aseemgautam]

• I have searched the issues of this repository and believe that this is not a duplicate.

Version

3.6.3

Environment

OSX High Sierra, Chrome

Reproduction link

Steps to reproduce

Dragger is configured to allow only jpeg files. Multiple attribute is set to true.
Click on the dragger and select one JPG file and any other file. One valid and one invalid file.

What is expected?

Begin upload for valid file and reject invalid file.

What is actually happening?

An exception the thrown in the console - Warning: Each child in an array or iterator should have a unique "key" prop. This error is also throws sometimes - Encountered two children with the same key, rc-upload-1529412272836-3

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Only occurs when valid and invalid files are selected. Works fine when all files are valid or invalid.

[aseemgautam]

Any update on this issue?

[zombieJ]

Hmmm, let me check...