I have had a dual boot Windows 10/Ubuntu Linux set up for many years, with Firefox installations in the two operating systems both using the same profile accessible on a shared a disk partition. Since a Ubuntu update several months ago, using Firefox under Ubuntu produces the "The bookmarks and history system will not be functional because one of Firefox's files is in use by another application. Some security software can cause this problem." problem when I revert to Windows and try to run Firefox under Windows. I can clear the problem by running a disk check in Windows on the shared partition, but does anyone know how to avoid this?