This error occurs for several reasons, one of them, and the most usual one is because the file .htaccess is already written.
Normally when they give us the hosting ]give us this file with several lines for the correct functioning of the host such as the extensions of frontpage . These lines can be deleted because if they were necessary for the operation of hosting this would recreate it. For that reason, we have always advised to eliminate the file and that way the problem was avoided.
After some time studying the reason of the problem and looking for the solution so as not to have to eliminate it, I found it:
WordPress when it generates the code it has to generate, instead of generating it in a new line, it generates it in the last line. Osease, share the line of WordPress with something else.
The good thing is that we only have to do this once since the next few times the code if it will be generated will be put in the right place.
That's right. What we see in most of the web 2.0 is illegal. This is confirmed by the Data Protection Agency.
It is not legal for something very simple, "this practice violates the Law of Services of the Information Society and Electronic Commerce (LSSI), which does not foresee can send any mail with advertising or promotional content ".
The Data Protection Agency has published a PDF on its website with the resolution of the complaint dating from day 20 February
In WP we can find a lot of plugins to do this function, there are also free services (like mi @ ) that offer that possibility. Any system either plugin external service, code php … is illegal.
If you have some similar system in your web I recommend removing it and if you have doubts about whether your system does not comply with the regulations, it would be for you to get in touch with the Data Protection Agency.