Thanks for your suggestion already. I copied the file to my desktop, but now it seems, although I have full access to all developer's features, I can't add a password to the file. I receive the message "To manage the security of this file, enter an account with Full Access privileges." Whatever I enter in "Account name" and "Password" fields, I can't, what is logical, as I never set this file like that. My guess is that I have to make a new file, this time password protected, and then importing one for one the necessary tables with their fields, layouts, scripts, relationships, etc. and then the content, or do you have any idea that is less labour consuming?
Best regards,
Jerome
p.s. Still amazed that what worked well for so long, suddenly the FMServer changed mood about me having access to the file. The date that you see on the screen shot of the file concerns the content of the dictionary and has nothing to do with the FileMaker version I work with, namely FM pro 15 Advanced 15.0.3.305 and FileMaker Server 15.0.3.308.