After installing FM Pro Advanced 18.104.22.168 I am getting (on occasion) the message that Filemaker has stopped working with long standing programs - anyone else experience this?
You could post a crash report.
(preferably as a text file linked here, not just pasted)
You can also test your file by doing a recover on a copy of it and then trying to open the recovered copy to see if that copy crashes.
I have seen such happen before when, apparently, some latent damage to the file does not cause observable problems for the user until they upgrade FM, Upgrade the OS, or change OS. Then that seems enough of a change for the latent damage to no longer be latent and you get a crash where you did not get it before.
This is not the only possible explanation, but one you can test on recovered copies of your files. (recover it using the latest version).
Shall we know your system config details ?
Retrieving data ...