I already have made such tests :it works. I have try to change the directories of the Traces and others (maps, elevation, ...) but no way !
I can create folders from oruxmaps (so writing is ok) but the error is already present.
I don't think it was a problem with the files but with the database witch may be corrupted !
Finally, I get my Phone back to original settings, loosing all my datas and configuration, and reinstall all the applications. After that, it works again like at the beginning when I fist install oruxmap on my phone !
If you have other ideas, or informations, about how the database is use, it could be useful because reseting a device is very uncomfortable for resolving this issue...
Best regards.
Dominique, Information System engineer in a SIG compagny.