Thank you for your post.
1. (and 2.) A primary ID could be repeated if you import from another file that contains the same primary ID. Is this the possible cause? If not, what can you tell me about the two clients that entered this information.
3. What is the ExecuteSQL statement being used?
4. There are two issues listed here. Updating layout objects across all layouts sounds like you want a global type of layout. True? But since each layout is specifically individualized, it sounds like you only want certain objects to be global across layouts. True? If either is the case, I would recommend posting this suggestion to the Product Ideas board at: Product Ideas
The Product Ideas board is monitored by Product Management and Development. All entries are read, discussed and considered for possible implementation in a future release.
Your example is a little different with adding a menu item. You can do this by creating a new menu, and have all layouts use that menu. When you add a new menu item to the menu set, then all layouts that use that menu set will be updated.
5 and 6. I don't know if ODBC can access the field options (auto-enter or field length). I have only used it to extract data. I have asked for more information from our Development and Testing departments. When I receive a reply, I will let you know.
Regarding #5 and #6, Testing is unable to reproduce the issue. In essence, a FileMaker Pro field has an auto-enter serial number. Using Microsoft Excel 2016 to insert a record into the FileMaker Pro table via the ODBC driver, the auto-enter setting was honored.
Testing wants to know how you are setting the auto-enter options in your FileMaker Pro file? Also, what application is being used to access the FileMaker Pro data? What version of FileMaker Pro is being used? What version of the ODBC driver is being used? Is this on Windows or Mac OS X?