I have an integration in Gen2 which is working fine but facing error in gen3 at stage write activity

Summary:

I have an integration which copies BI data to a file . The integration is working fine in OIC Gen2 instance . Recently we upgraded to gen3 and the integration is throwing error at stage write activity.
Can someone help why this behaviour?

Below is my xslt -

<xsl:template match="/" xml:id="id_11">
<xsl:variable name="lineBreak">
<xsl:value-of select="' '"/>
</xsl:variable>
<nstrgmpr:Write xml:id="id_12">
<xsl:value-of select="$lineBreak"/>
<xsl:copy-of select="$readFile/nsmpr0:ReadResponse/ns20:ROWSET/ns20:ROW/ns20:_B1/node()"/>
</nstrgmpr:Write>
</xsl:template>

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