Trouble saving excel files on remote network server 2012

I have a few people outside the network who connect to our network via VPN (sonicwall SSL VPN). There were few if any problems until I switched file servers from server 2003 to server 2012.  Now all the sudden I have horrible file locking and saving issues. Some errors that are occurring very often but not all the time:

When a file is opened, they get the error: " cannot be accessed. The file may be corrupted, located on a server that is not responding, or read only. (note the ")  if they hit 'retry' a few times the spreadsheet appears to open

When a file is saved, they get the error: "[file in question] is currently in use. Try again later"

Most times they can retry the save a few times, and eventually it will actually save. Other times they get that error every time until they give up.  Local users are not reporting any problems with saving and opening files. Overall performance over the VPNs has also dropped dramatically. It can literally take 2 minutes to open a 70k file.

I have verified that the user I am testing with has a 100 meg pipe. Throughput doesn't seem to be an issue. Everything started happening as soon as I started using server 2012 as a file server. I have verified that nobody has these files open during my tests. I've noticed that looking at the file locks, sometimes I have a read-write lock with a user of [disconnected] for some of these files.

Can anybody give me a clue as to where to start troubleshooting this issue?
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

ProfessorJimJamMicrosoft Excel ExpertCommented:
Do you have EFS settings which is mandated via Group Policy in Windows domain environments?

you maybe have this issue only with the Save option Not Save As.  do you get same problem with Save As new file?

For "Save As" as new workbook
 When you save an existing file in Excel, Excel creates a temporary file in the destination folder that you specify in the Save As dialog box. The temporary file contains the whole contents of your workbook. If Excel successfully saves the temporary file, the temporary file is renamed with the file name you specify in the Save As dialog box.

For "Save" existing file
This process of saving files makes sure that the original file is not damaged. The original file is useful if the save operation is not successful.
When Excel saves a file, Excel follow these steps: 1.Excel creates a randomly named temporary file (for example, Cedd4100 with no file name extension) in the destination folder that you specified in the Save As dialog box. The whole workbook is written to the temporary file.
2.If changes are being saved to an existing file, Excel deletes the original file.
3.Excel renames the temporary file. Excel gives the temporary file the file name that you specified (such as Book1.xls) in the Save As dialog box.
Important Points About Saving
• After Excel creates and saves the temporary file, all the changes are written to the temporary file.
•If Excel cannot delete the existing file, you receive an error message. The original file and the temporary file both remain in the destination folder.
•If Excel can delete the existing file, but Excel cannot rename the temporary file, you receive an error message. Only the temporary file remains in the destination folder.
•If Excel saves a new file for the first time, Excel does not create a temporary file. Excel saves the file with the file name that you specified in the Save As dialog box.

Microsoft Excel creates temp files sometimes with and without extensions when saving.  Some real-time scanning programs, some antivirus or syncing or  indexing applications detect these temp files and attempt to read their contents, and while doing so the lock the files. This causes immediate problems when its parent application tries to convert the temp file back to its intended format.

there is also a similar question answer in Experts Exchange that might be of help as well.

there is a good article about  Antivirus causing this issue.

another article that might be helpful for saving files being slow caused by EFS

hope it helps.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
twinsteadAuthor Commented:
Thanks for all your helpful advice. After careful examination it does appear that the VPN must somehow be the culprit, because when I connected to the same server via a VPN to another server in a trusted domain in a different location (connected to the file server in question via a point-to-point connection) the issue disappeared. So, the errors only occur when I am connected to a specific sonicwall.

I checked and the settings for both VPNs are identical, but I was able to get around it by having them connect to another location and pull it across the point-to-point.

So, still a problem just probably not a file server problem. A double-edged sword--problem is short-term solved, but long term I'm still stumped
Martin LissOlder than dirtCommented:
This question has been classified as abandoned and is closed as part of the Cleanup Program. See the recommendation for more details.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.