Ubuntu 1.14 recovery mode ((Drm_kms_helper:panic occurred,switching back to text console

I updated the operating system ubuntu. 14 (version 2.02~beta2-9)) When I restart my laptob I have this error.👇

. .error

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Drm_kms_helper:panic occurred,switching back to text console
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I googled and find this tutorial

But dosen't help me.I try recovery my operating system.I have not boot cd or USB .it is possible I'll go back to the last update???

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