Database error when creating child site

[Bits Support]

Hello,

I tried to create a child site but when I have copy db and copy files it gives me this db error:

Fatal error: Out of memory (allocated 730857472) (tried to allocate 86 bytes) in /home/XXXXX/domains/XXXXX.net/public_html/libraries/joomla/database/database/mysql.php on line 462

Can anyone tell me what I am doing wrong or what I need to do? Current php memory limit is set to 812M.

Thanks

EDIT: Also when I delete that copy I get another error:

JFolder::delete: Path is not a folder

any help please and thank you

EDIT2: I was instructed to give up on this extention. Can someone tell me what I need to do to remove it from my Joomla installation?