If you want to replace a keyword with a string using sedsed, sedsed tries hard to interpret your replacement string. If the replacement string happens to have characters that sedsed considers special, like a '/'/ character, it will fail, unless of course you meant your replacement string to have characters that tell sedsed how to act.
Ex:
VAR="hi/"
sed "s/KEYWORD/$VAR/g" somefile
Is there any way to tell sedsed not to try to interpret the replacement string for special characters? All I want is to be able to replace a keyword in a file with the contents of a variable, no matter what that content is.