When Windows Explorer or anothe application has the Briefcase open, and I try to open or save a file into the Briefcase with another application I get the error message: "The Briefcase is in use on another computer" "Close the Briefcase on that computer, and then try again."

Hi , Did you make any changes before this issue occurs? Please temporarily disable all the third party security programs even if firewall and boot in Clean Boot to test the issue. If no progress, I suggest you synchronize files stored on a removable disk using Briefcase. 1.Insert a removable disk into a disk drive on your main computer. 2.Open Briefcase, and then copy the appropriate files to Briefcase. 3.Drag Briefcase to the disk. The files in Briefcase are copied to the disk. 4.Remove the disk from your main computer and insert it into a disk drive on your portable computer. 5.Open Briefcase from the disk and work on the files. When you are ready to synchronize the files, remove the disk from your portable computer and reinsert it into a disk drive on your main computer. 6.Open Briefcase from the disk, and then do one of the following: To update all the files, on the Briefcase menu, click Update All. To update only some of the files, select the files you want to update, and then on the Briefcase menu, click Update Selection. Please see Sync using Briefcase for more information.Tracy Cai TechNet Community Support

Hi , Did you make any changes before this issue occurs? Please temporarily disable all the third party security programs even if firewall and boot in Clean Boot to test the issue. If no progress, I suggest you synchronize files stored on a removable disk using Briefcase. 1.Insert a removable disk into a disk drive on your main computer. 2.Open Briefcase, and then copy the appropriate files to Briefcase. 3.Drag Briefcase to the disk. The files in Briefcase are copied to the disk. 4.Remove the disk from your main computer and insert it into a disk drive on your portable computer. 5.Open Briefcase from the disk and work on the files. When you are ready to synchronize the files, remove the disk from your portable computer and reinsert it into a disk drive on your main computer. 6.Open Briefcase from the disk, and then do one of the following: To update all the files, on the Briefcase menu, click Update All. To update only some of the files, select the files you want to update, and then on the Briefcase menu, click Update Selection. Please see Sync using Briefcase for more information.Tracy Cai TechNet Community Support