我和朋友联机时，他那边可以看见页面，但是一播放视频就白屏了 而我这边却完全没有问题。他的游戏文件是我发的，文件和配置什么的一定是一样的，是什么导致了这个问题呢？

当我在CatServer1.12.2服务器端添加它时服务器提示以下错误

[11:15:41] [Server thread/ERROR] [net.minecraft.server.MinecraftServer]: Encountered an unexpected exception

net.minecraftforge.fml.common.DuplicateModsFoundException:

Duplicate Mods:

mcef : E:\CatServer-v21.12.18.\mods\MCEF_v1.11.jar

mcef : E:\CatServer-v21.12.18.\mods\MCEF_v1.11.jar

at net.minecraftforge.fml.common.Loader.identifyDuplicates(Loader.java:466) ~[Loader.class:git-CatServer-1.12.2-2bce5d5]

at net.minecraftforge.fml.common.Loader.identifyMods(Loader.java:428) ~[Loader.class:git-CatServer-1.12.2-2bce5d5]

at net.minecraftforge.fml.common.Loader.loadMods(Loader.java:568) ~[Loader.class:git-CatServer-1.12.2-2bce5d5]

at net.minecraftforge.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:97) ~[FMLServerHandler.class:git-CatServer-1.12.2-2bce5d5]

at net.minecraftforge.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:336) ~[FMLCommonHandler.class:git-CatServer-1.12.2-2bce5d5]

at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:168) ~[nz.class:?]

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:634) [MinecraftServer.class:?]

at java.lang.Thread.run(Unknown Source) [?:1.8.0_181]

[11:15:42] [Server thread/ERROR] [net.minecraft.server.MinecraftServer]: This crash report has been saved to: E:\CatServer-v21.12.18.\crash-reports\crash-2021-12-29_11.15.42-server.txt

[11:15:42] [Server thread/INFO] [net.minecraft.server.MinecraftServer]: Stopping server

[11:15:42] [Server thread/INFO] [net.minecraft.server.MinecraftServer]: Saving worlds

[11:15:42] [Server thread/INFO] [FML]: The state engine was in incorrect state CONSTRUCTING and forced into state SERVER_STOPPED. Errors may have been discarded.

网页可以加载而且也可以点但是就是无法显示直接白屏