When there are special characters in the action url, yo may get such error as "BadUrlList thrown by UrlFileParser...".
The resolution is using HTTP URL Encode. Syntax example is as below,
Original URL:
1 GET http://192.168.58.2/login.html?data=1&user=robert&password=hisome*$@/bg\l;a
Using URL encode:
ASSIGN VARIABLE <mayvar1 "user=robert&password=hisome*$@/bg\l;a">
1 GET http://192.168.58.2/login.html?data=1&<APPLY URLENC HEADER mayvar1>