Preferences file could not be read

[dhardy]

Describe the bug
On first start (or after deleting client.prefs), the client starts as expected. On subsequent starts (whether or not any settings have been changed in the UI), the game fails to start with the following log message:

2021-05-20 17:40:53.727  WARN 252182 --- [JavaFX-Launcher] c.f.c.preferences.PreferencesService     : Preferences file /home/dhardy/.faforever/client.prefs could not be read

java.lang.reflect.InaccessibleObjectException: Unable to make field private final java.lang.String java.net.HttpCookie.name accessible: module java.base does not "opens java.net" to unnamed module @470e2030
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:357)
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:297)
	at java.base/java.lang.reflect.Field.checkCanSetAccessible(Field.java:177)
	at java.base/java.lang.reflect.Field.setAccessible(Field.java:171)
	at com.google.gson.internal.reflect.UnsafeReflectionAccessor.makeAccessible(UnsafeReflectionAccessor.java:44)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:159)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:102)
	at com.google.gson.Gson.getAdapter(Gson.java:458)
	at com.google.gson.internal.bind.CollectionTypeAdapterFactory.create(CollectionTypeAdapterFactory.java:53)
	at com.google.gson.Gson.getAdapter(Gson.java:458)
	at com.google.gson.internal.bind.MapTypeAdapterFactory.create(MapTypeAdapterFactory.java:126)
	at com.google.gson.Gson.getAdapter(Gson.java:458)
	at com.google.gson.Gson.fromJson(Gson.java:926)
	at com.google.gson.Gson.fromJson(Gson.java:994)
	at com.google.gson.internal.bind.TreeTypeAdapter$GsonContextImpl.deserialize(TreeTypeAdapter.java:162)
	at com.faforever.client.preferences.gson.PropertyTypeAdapter.deserialize(PropertyTypeAdapter.java:123)
	at com.faforever.client.preferences.gson.PropertyTypeAdapter.deserialize(PropertyTypeAdapter.java:41)
	at com.google.gson.internal.bind.TreeTypeAdapter.read(TreeTypeAdapter.java:69)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:131)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:222)
	at com.google.gson.Gson.fromJson(Gson.java:927)
	at com.google.gson.Gson.fromJson(Gson.java:865)
	at com.faforever.client.preferences.PreferencesService.readExistingFile(PreferencesService.java:254)
	at com.faforever.client.preferences.PreferencesService.afterPropertiesSet(PreferencesService.java:173)

That doesn't sound like an error in the preferences file to me?

Other than that the client seems to work okay (able to launch games).

To Reproduce
Installed on Fedora Linux as per instructions (except using openjdk 16 from Fedora packages, which I have successfully used in the past).

OS
Fedora Linux 34

[dhardy]

It turns out the prefs file ended eight lines short (line 125 of 133). Adding } to the end was enough to make the client start.

No idea why this happened (repeatedly), but I might as well close this.

[dhardy]

This is not solved. Usually the lua file is syntactically valid but still fails to load, as above.

[Brutus5000]

We encountered the same if we run the client on Java 16. Are you sure you run on java 15 ?

[Sheikah45]

Brutus beat me to asking about the java version

[dhardy]

Yes, running on Java 16.

[Sheikah45]

Yes then you need to run with java 15 as we are not yet compatible with java 16

[dhardy]

Aha, thanks.