Creating new user in windows will not help, has nothing to do with filemaker networking. The database has to be open and running on the hosting computer and the other computer connects from within filemaker using open remote.
The thing is, that creating new users in windows DID work. From a fresh user I can reach my database and use it. All the other connected computers can also use it and se my changes.
In any case, using file sharing to access and share a FileMaker Database file is strongly recommended against by FileMaker Techs. According to them this method risks damaging the computer file. Using Open Remote to access the database after it has been opened by FileMaker or FIleMaker Server that has been installed on the same computer where the file is located is the recommended method.
If the first person to access the file is opening it directly and the second user then uses Open Remote, you still risk this issue, but if one User has FileMaker Sharing enabled and the Other does not, you might get this error.
But a more detailed description of how you are attempting to access and open the file would be helpful.
Thansk for the answers.
I got a file from my serverhost that I use to connect to the database. I was the first to try out Filemaker pro 12, and it did not work.
The thing is, it seems to work for everbody else, so I can live with having two users on my personal computers :)
Thanks again! :)