You should only need to enter it once.
Are you opening only a single file or do you have additional files--perhaps linked with external data source references?
Is there a script set to run "onFIrstWindowOpen" in File Options of this file?
I am opening a single file and no II dont think so...if possible I can do a share screen so you may view and there ae no expernal data sources
Just open Manage | External Datasources. If there is nothing listed, then you don't have any.You can use the controls below Post a New answer to upload a screen shot of this window if you do find external data sources for your file.
You can check the script triggers tab of File Options to see if a script is being performed when you open the file.
You may need to launch FileMaker without opening this file and then use Recover from the File Menu to see if Recover finds any problems with this file.