I have a workbook that my team uses, we have used this workbook for months. Every month I just Save As for the new month. One user when she opens the shared file it was an extra blank sheet added in between my #2 & #3 sheet. It is a blank "sheet1". On one worksheet, her rows stop at row 340. Even though no rows are hidden.

The other user, when opening the shared workbook has a worksheet that they cannot see.

If I unshare and they open it as read only, then it works fine. But the instant I share it, it breaks. I have other users, but I have not checked their workbooks.