for others I found the solution
if you have a %27 in the string BPS security blocks, make sure all rewrite query strings you remove %27
# BEGIN BPSQSE BPS QUERY STRING EXPLOITS
# The libwww-perl User Agent is forbidden - Many bad bots use libwww-perl modules, but some good bots use it too.
# Good sites such as W3C use it for their W3C-LinkChecker.
# Use BPS Custom Code to add or remove user agents temporarily or permanently from the
# User Agent filters directly below or to modify/edit/change any of the other security code rules below.
RewriteCond %{HTTP_USER_AGENT} (havij|libwww-perl|wget|python|nikto|curl|scan|java|winhttp|clshttp|loader) [NC,OR]
RewriteCond %{HTTP_USER_AGENT} (%0A|%0D|%3C|%3E|%00) [NC,OR]
RewriteCond %{HTTP_USER_AGENT} (;|<|>|'|"|\)|\(|%0A|%0D|%22|%27|%28|%3C|%3E|%00).*(libwww-perl|wget|python|nikto|curl|scan|java|winhttp|HTTrack|clshttp|archiver|loader|email|harvest|extract|grab|miner) [NC,OR]
RewriteCond %{THE_REQUEST} (\?|\*|%2a)+(%20+|\\s+|%20+\\s+|\\s+%20+|\\s+%20+\\s+)(http|https)(:/|/) [NC,OR]
RewriteCond %{THE_REQUEST} etc/passwd [NC,OR]
RewriteCond %{THE_REQUEST} cgi-bin [NC,OR]
RewriteCond %{THE_REQUEST} (%0A|%0D|\\r|\\n) [NC,OR]
RewriteCond %{REQUEST_URI} owssvr\.dll [NC,OR]
RewriteCond %{HTTP_REFERER} (%0A|%0D|%3C|%3E|%00) [NC,OR]
RewriteCond %{HTTP_REFERER} \.opendirviewer\. [NC,OR]
RewriteCond %{HTTP_REFERER} users\.skynet\.be.* [NC,OR]
RewriteCond %{QUERY_STRING} [a-zA-Z0-9_]=(http|https):// [NC,OR]
RewriteCond %{QUERY_STRING} [a-zA-Z0-9_]=(\.\.//?)+ [NC,OR]
RewriteCond %{QUERY_STRING} [a-zA-Z0-9_]=/([a-z0-9_.]//?)+ [NC,OR]
RewriteCond %{QUERY_STRING} \=PHP[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12} [NC,OR]
RewriteCond %{QUERY_STRING} (\.\./|%2e%2e%2f|%2e%2e/|\.\.%2f|%2e\.%2f|%2e\./|\.%2e%2f|\.%2e/) [NC,OR]
RewriteCond %{QUERY_STRING} ftp\: [NC,OR]
RewriteCond %{QUERY_STRING} (http|https)\: [NC,OR]
RewriteCond %{QUERY_STRING} \=\|w\| [NC,OR]
RewriteCond %{QUERY_STRING} ^(.*)/self/(.*)$ [NC,OR]
RewriteCond %{QUERY_STRING} ^(.*)cPath=(http|https)://(.*)$ [NC,OR]
RewriteCond %{QUERY_STRING} (\<|%3C).*script.*(\>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (<|%3C)([^s]*s)+cript.*(>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (\<|%3C).*embed.*(\>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (<|%3C)([^e]*e)+mbed.*(>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (\<|%3C).*object.*(\>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (<|%3C)([^o]*o)+bject.*(>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (\<|%3C).*iframe.*(\>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} (<|%3C)([^i]*i)+frame.*(>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} base64_encode.*\(.*\) [NC,OR]
RewriteCond %{QUERY_STRING} base64_(en|de)code[^(]*\([^)]*\) [NC,OR]
RewriteCond %{QUERY_STRING} GLOBALS(=|\[|\%[0-9A-Z]{0,2}) [OR]
RewriteCond %{QUERY_STRING} _REQUEST(=|\[|\%[0-9A-Z]{0,2}) [OR]
RewriteCond %{QUERY_STRING} ^.*(<|>|%3c|%3e).* [NC,OR]
RewriteCond %{QUERY_STRING} ^.*(\x00|\x04|\x08|\x0d|\x1b|\x20|\x3c|\x3e|\x7f).* [NC,OR]
RewriteCond %{QUERY_STRING} (NULL|OUTFILE|LOAD_FILE) [OR]
RewriteCond %{QUERY_STRING} (\.{1,}/)+(motd|etc|bin) [NC,OR]
RewriteCond %{QUERY_STRING} (localhost|loopback|127\.0\.0\.1) [NC,OR]
RewriteCond %{QUERY_STRING} (<|>|'|%0A|%0D|%3C|%3E|%00) [NC,OR]
RewriteCond %{QUERY_STRING} concat[^\(]*\( [NC,OR]
RewriteCond %{QUERY_STRING} union([^s]*s)+elect [NC,OR]
RewriteCond %{QUERY_STRING} union([^a]*a)+ll([^s]*s)+elect [NC,OR]
RewriteCond %{QUERY_STRING} \-[sdcr].*(allow_url_include|allow_url_fopen|safe_mode|disable_functions|auto_prepend_file) [NC,OR]
RewriteCond %{QUERY_STRING} (;|<|>|'|"|\)|%0A|%0D|%22|%3C|%3E|%00).*(/\*|union|select|insert|drop|delete|update|cast|create|char|convert|alter|declare|order|script|set|md5|benchmark|encode) [NC,OR]
RewriteCond %{QUERY_STRING} (sp_executesql) [NC]
RewriteRule ^(.*)$ - [F]
# END BPSQSE BPS QUERY STRING EXPLOITS
ref:
https://forum.ait-pro.com/forums/topic/feedburner-error/
