Writing permissions denied

I have been working with julia about one year now.
From a couple of days, I can start and work on my .jl files for a while, saving them regularly. However, after a few saving actions, I suddenly I can’t save them anymore (permission denied error).
I use Atom 1.38.2 as editor and work on windows 10 Pro.
I though it was an Atom problem at first, but the error reproduces when I open atom in safe mode. Also, even after closing atom, I still can’t delete or edit the file.
The only thing that solves the problem is restarting my laptop. But again, the error repeats after a while I am working. Does anyone have an idea what’s going on?

The file is probably locked by some process which is still running and blocks writing access to the file.
You may look into the task manager to see if there a some unexpected processes still running.

And you can use the Ressource Monitor to find out about open file handles: resmon.exe

On the CPU Tab mark all processes and enter the filename into the lower right text box (search handles or similar).