RVSitebuilder internal server error in some of the templates

Hi,

I have issue in the RVsite builder when trying to change some of the templates. i got the internal server error when use most of the templates. I am using the latest cpanel version 11.40.0 and RVSite builder version 5.2.6.

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error:
Internal Server Error

500

No response from subprocess (php): subprocess was killed with signal 6
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Could someone please tell me what is causing the issue or this is a bug.