problem at the beginning of the upgrade 4.2 to 5.1

[Emad ELsayed]

At the beginning of the upgrade 4.2 to 5.1
When click on the Begin Upgrade to appear the following error

Action Required
Unexpected Text:    <br /> <b>Deprecated</b>:  preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in <b>/home/new321/public_html/vb51/core/includes/functions.php</b> on line <b>4278</b><br /> <?xml version="1.0" encoding="windows-1252"?> <upgrade> <message replace="0">Creating routenew table</message> <status>Status: Processing 5.0.0 Alpha 1, Step 4 of 166</status> <longversion>5.0.0 Alpha 1</longversion> <version>500a1</version> <nextstep>4</nextstep> <upgradenotice><![CDATA[<strong>Upgrading to 5.0.0 Alpha 1</strong>]]></upgradenotice> </upgrade>

I hope help me solve this problem

[Mark.B]

Please do not upgrade to 5.1.

You need to use 5.2.5.

5.1 is completely unsupported.