I upgraded my MacBook 15" to OS10.14 Mojave and discovered that FMP Adv 14 is not compatible.
So I downloaded the trial version of FMP17 and opened my database file and it asked for my user name and password which is usual.
However it does not accept my user name and password as it did when previously opened by FMP14.
I have restored the data file from my Time Machine backup from before the Mojave install.
Message I get is..."The provided account name and password cannot be used to access this file."