# File Lock Issue **URL:** \ **Category:** SketchUp\ **Created:** [March 16, 2015, 4:15am UTC](https://forums.sketchup.com/t/file-lock-issue/8545 "2015-03-16T04:15:02Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![jj0gen0info](https://avatars.discourse-cdn.com/v4/letter/j/a587f6/32.png) [@jj0gen0info](https://forums.sketchup.com/u/jj0gen0info)\ **Post date:** [March 16, 2015, 4:15am UTC](https://forums.sketchup.com/t/file-lock-issue/8545/1 "2015-03-16T04:15:02Z")
When I tried to open a second SketchUp file in another instance of SketchUp, a notification pops-up stating that the file was already open by another user, do I want to open it as read-only. Since the second file was not opened before and I’m the only user on the PC something was wrong. After having closed all Apps, I tried again, but got the same message. However, when I tried to open another SketchUp file I got a different message; the file was in use by a “COM Surrogate”. In the Task-Manager there were three Com-Surrogates running; I ended one and was then able to open both the “Locked” file and the other messaging about the COM-Surrogate. It appears that SketchUp may not be terminating properly in certain instances; leaving hooks. ---
**Author:** ![Box](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/box/32/235164_2.png) [@Box](https://forums.sketchup.com/u/Box)\ **Post date:** [March 16, 2015, 5:07am UTC](https://forums.sketchup.com/t/file-lock-issue/8545/2 "2015-03-16T05:07:34Z")
Might be related to this thread. > [@"File currently locked by another user" error in Windows Explorer](http://forums.sketchup.com/t/file-currently-locked-by-another-user-error-in-windows-explorer/6999): > > We have found a bug that has a workaround. The “file currently locked by another user” message seen when the preview pane in windows explorer is open and the file is opened by double clicking. Some people get a “read only” version when opening. To see the issue, you need to have the Preview pane open (which is turned off by default - which is a good thing - on Win 7, Win 8 and Win 10), Windows Explorer needs to be set to a thumbnail view, the model needs to have a thumbnail and the user needs t… ---
**Author:** ![jj0gen0info](https://avatars.discourse-cdn.com/v4/letter/j/a587f6/32.png) [@jj0gen0info](https://forums.sketchup.com/u/jj0gen0info)\ **Post date:** [March 16, 2015, 2:13pm UTC](https://forums.sketchup.com/t/file-lock-issue/8545/3 "2015-03-16T14:13:19Z")
Firstly, the “Preview Pane” was never open in the Windows Explorer on the Windows 8.1 PC in question. However, I do have “Thumbnails” displayed. This has happened more then once, but it only seems to happen if I open multiple instances of SketchUp. I have never experienced this problem with multiple instances of other programs. Again, what appeared to have cleared up the problem was terminating one of the COM-Surrogates that were running. Attempts to terminate any of the remaining COM-Surrogates are protected and blocked by the system. The issue appears to be the orphaned COM-Surrogate. My work around is to kill the orphaned COM-Surrogate. ---
**Author:** ![Box](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/box/32/235164_2.png) [@Box](https://forums.sketchup.com/u/Box)\ **Post date:** [March 16, 2015, 2:49pm UTC](https://forums.sketchup.com/t/file-lock-issue/8545/4 "2015-03-16T14:49:02Z")
Firstly I said might. ---
**Author:** ![jj0gen0info](https://avatars.discourse-cdn.com/v4/letter/j/a587f6/32.png) [@jj0gen0info](https://forums.sketchup.com/u/jj0gen0info)\ **Post date:** [March 16, 2015, 4:08pm UTC](https://forums.sketchup.com/t/file-lock-issue/8545/5 "2015-03-16T16:08:33Z")
Sorry, didn’t mean to sound critical. I did appreciate your response. I hope the developers read this thread, as it may give them a clue to a solution.