When you double-click on an .anatella file that is already opened inside an Anatella window “X”, your operating system (i.e. MS-Windows) won’t open a new Anatella window but it will rather put “top-most” the Anatella window “X” (This prevents a complete mess where you would be editing the same graph in different windows).
The above mechanism is provided by the “Anatella Server”. The “Anatella Server” is a very small executable that runs in the background. It keeps track of which process opened which .anatella file. It also sets the required MS-Windows file associations (e.g. all .anatella files must be associated with the “AnatellaServer.exe” process).
If the “Anatella Server” is frozen, you won’t be able to open any new .anatella file for edition. In such situation, close all opened .anatella files and kill the “Anatella Server”. Alternatively, you can also “manually” kill the “AnatellaServer.exe” process using the “MSWindows Task Manager”:
If no “AnatellaServer.exe” process is running, MS-Windows will transparently (re-)launch a new “AnatellaServer.exe” process as soon as you open an .anatella file. Usually, you don’t have to worry about the “Anatella Server”: everything is automated and transparent to the user.