I have been playing on the 1.12.2 version of Pixelmon for about a week, without knowing 1.16.5 was available. When I updated versions it became unplayable. Any time I would enter a battle and hover over the UI, which in turn would create the custom cursor, the entire game would crash back to the launcher. I tried troubleshooting with the discord, which led to the discovery of the issue, without being able to find any actual solution.

Below is the crash log.

https://pastebin.com/T2aQa7JQ

Moving to internal for further investigation. Will be using this as the master ticket

https://pixelmonmod.com/tracker.php?p=2&t=18131
https://pixelmonmod.com/tracker.php?p=2&t=18454

Will edit this ticket with more reports when possible

I forgot to come back and post my findings and solution to my ticket. This bug is caused by having more than one instance of Technic installed on your hard drive. If you partition a new section or just delete all your old files this bug will go away. For whatever reason the current version of pixelmon doesn't pull from the right file if you have had old versions installed. You have to delete all files including the ones in the .technic and .minecraft folders.

I tried what Ulffgar suggested and had my file manager search for every instance of "Pixelmon" on my computer. I deleted every single instance that appeared. After this, I installed a fresh version of 1.16.5 Pixelmon. The game continued to crash when the custom Pixelmon cursor hovered over the custom UI.

I didn't say to look for other instances of Pixelmon. I stated my issue was resolved when deleting other instances of the Technic Launcher and its contents. Deleting Pixelmon and all files related to it didn't do anything. What was happening is that having multiple versions/locations of Technic on my pc caused an error with the mouse. I didn't test to see if it was specifically pixelmon only or all technic mods that have custom cursors. Regardless if what worked for me doesn't work for you I apologize but again I didn't say delete pixelmon.

I've had a similar problem. Here's the crashlog:
https://pastebin.com/Tr4u7jME

I've already mentioned this in the discord, but I wanted to a put it here as well.

Whenever I mouse over an attack in a battle it just hard crashes to the launcher giving me an exit code 1 error.

One thing I noticed rooting around the log file is that it seems to not be finding the custom cursor that the mod uses. I don't know why. If you look in the pastebin it's at 321

[27Aug2022 23:26:31.744] [main/ERROR] [Pixelmon/]: Failure in setting cursor!

That may be causing the crash.

Either way, if anyone knows how to fix this, please let me know asap.

To anyone having this issue, can you see if using MultiMC works?

I wouldn’t be able to check until this weekend. However, if nobody has checked before then I can.

I have tried to launch with MultiMC as requested. I installed PixelmonReforged through the ATLauncher option as that was the first one I saw.

Here is the relevant part of the log to avoid making the ticket too long (and pastebin would not allow me to paste the entire log in, DM on discord if you would like the full log)

[13:18:15] [main/INFO] [minecraft/NewChatGui]: [CHAT] You have found a village!
[13:18:53] [main/INFO] [minecraft/NewChatGui]: [CHAT] You found one Grip Claw!
[13:18:59] [main/INFO] [minecraft/NewChatGui]: [CHAT] You sent out Chikorita!
[13:19:01] [main/ERROR] [Pixelmon/]: Failure in setting cursor!
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: java.io.FileNotFoundException: textures/gui/battle/pointer.png
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at net.minecraft.resources.VanillaPack.func_195761_a(VanillaPack.java:120)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper.lambda$static$3(CursorHelper.java:73)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper$$Lambda$4950/1358956741.get(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper.setCursor(CursorHelper.java:97)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at com.pixelmonmod.pixelmon.client.gui.ScreenHelper.drawBattleCursor(ScreenHelper.java:1665)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at com.pixelmonmod.pixelmon.client.gui.battles.battleScreens.ChooseAttack.render(ChooseAttack.java:143)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at com.pixelmonmod.pixelmon.client.gui.battles.BattleScreen.func_230430_a_(BattleScreen.java:436)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at net.minecraftforge.client.ForgeHooksClient.drawScreenInternal(ForgeHooksClient.java:377)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at net.minecraftforge.client.ForgeHooksClient.drawScreen(ForgeHooksClient.java:370)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at sun.reflect.GeneratedMethodAccessor15.invoke(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at java.lang.reflect.Method.invoke(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at net.optifine.reflect.Reflector.callVoid(Reflector.java:789)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at net.minecraft.client.renderer.GameRenderer.func_195458_a(GameRenderer.java:821)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at net.minecraft.client.Minecraft.func_195542_b(Minecraft.java:977)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:607)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at net.minecraft.client.main.Main.main(Main.java:184)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at java.lang.reflect.Method.invoke(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at net.minecraftforge.fml.loading.FMLClientLaunchProvider.lambda$launchService$0(FMLClientLaunchProvider.java:51)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at net.minecraftforge.fml.loading.FMLClientLaunchProvider$$Lambda$515/1092378530.call(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at cpw.mods.modlauncher.Launcher.run(Launcher.java:82)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at cpw.mods.modlauncher.Launcher.main(Launcher.java:66)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at java.lang.reflect.Method.invoke(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at io.github.zekerzhayard.forgewrapper.installer.Main.main(Main.java:57)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at java.lang.reflect.Method.invoke(Unknown Source)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at org.multimc.onesix.OneSixLauncher.launchWithMainClass(OneSixLauncher.java:210)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at org.multimc.onesix.OneSixLauncher.launch(OneSixLauncher.java:245)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at org.multimc.EntryPoint.listen(EntryPoint.java:143)
[13:19:01] [main/INFO] [STDERR/]: [com.pixelmonmod.pixelmon.api.util.helpers.CursorHelper:lambda$static$3:90]: at org.multimc.EntryPoint.main(EntryPoint.java:34)
#
# A fatal error has been detected by the Java Runtime Environment:
#
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x00007ff951fcb874, pid=9256, tid=33092
#
# JRE version: Java(TM) SE Runtime Environment (8.0_51-b16) (build 1.8.0_51-b16)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (25.51-b03 mixed mode windows-amd64 compressed oops)
# Problematic frame:
# C [glfw.dll+0xb874]
#
# Failed to write core dump. Minidumps are not enabled by default on client versions of Windows

What if you don't use the modpack?
On MultiMC, install forge first then just the Pixelmon mod.