If your server compile with suhosin, you also need to configure suhosin to allow RVsiteBuilder works properly.
Warning from suhosin
suhosin[8773]: ALERT - configured request variable name length limit exceeded - dropped variable '/var/cpanel/rvglobalsoft/rvsitebuilder/scripts/RVSeagullMod-1_0_1_tgz' (attacker 'REMOTE_ADDR not set', file 'unknown')
Set the following suhosin options in php.ini to fix the suhosin errors.
CODE
[suhosin]
; For translation manager to handle more inputs
suhosin.post.max_vars = 2000
suhosin.request.max_vars = 2000
; For URL handling
suhosin.request.max_totalname_length = 300
suhosin.request.max_varname_length = 300
suhosin.get.max_varname_length = 300
suhosin.get.max_name_length = 300
Increase the value as you need it. And don't forget to restart apache.