Java HotSpot(TM) Client VM warning: Using incremental CMS is deprecated and will like

most clients wont work the crash report is:

[02:10:25] [Client thread/INFO]: Setting user: (withheld)
[02:10:25] [Client thread/INFO]: (Session ID is token:82ebfe440bf94bcf939fec289a462043:ce3c0c10856 942ca908663b1eb7a1d0f)
Exception in thread "Client thread" com.google.gson.JsonSyntaxException: java****.EOFException: End of input at line 1 column 109
at com.google.gson.Gson.fromJson(Gson.java:813)
at com.google.gson.Gson.fromJson(Gson.java:768)
at net.minecraft.server.management.PlayerProfileCache .load(PlayerProfileCache.java:270)
at net.minecraft.server.management.PlayerProfileCache .<init>(PlayerProfileCache.java:89)
at net.minecraft.server.MinecraftServer.<init>(Minecr aftServer.java:192)
at net.minecraft.server.integrated.IntegratedServer.< init>(IntegratedServer.java:52)
at net.minecraft.client.Minecraft.<init>(Minecraft.ja va:383)
at net.minecraft.client.main.Main.main(Main.java:115)
Caused by: java****.EOFException: End of input at line 1 column 109
at com.google.gson.stream.JsonReader.nextNonWhitespac e(JsonReader.java:1377)
at com.google.gson.stream.JsonReader.doPeek(JsonReade r.java:456)
at com.google.gson.stream.JsonReader.hasNext(JsonRead er.java:403)
at com.google.gson.internal.bind.CollectionTypeAdapte rFactory$Adapter.read(CollectionTypeAdapterFactory .java:80)
at com.google.gson.internal.bind.CollectionTypeAdapte rFactory$Adapter.read(CollectionTypeAdapterFactory .java:60)
at com.google.gson.Gson.fromJson(Gson.java:803)
... 7 more
Java HotSpot(TM) Client VM warning: Using incremental CMS is deprecated and will likely be removed in a future release