Error with APIs in 1.12.2

[GoogleClasses]

Versions
Plugin: 7.0 | PaperMC 1.12.2

Describe the bug
There are errors with the 1.13+ Spigot API and things like GUI items with commands don't work.

[10:15:21 WARN]: [VotingPlugin] Plugin VotingPlugin v7.0 generated an exception while executing task 6007015 java.lang.NoClassDefFoundError: org/bukkit/Registry at com.bencodez.votingplugin.advancedcore.AdvancedCoreConfigOptions.getClickSoundSound(AdvancedCoreConfigOptions.java:304) ~[?:?] at com.bencodez.votingplugin.advancedcore.api.inventory.BInventory.playSound(BInventory.java:648) ~[?:?] at com.bencodez.votingplugin.advancedcore.api.inventory.BInventory.onClick(BInventory.java:507) ~[?:?] at com.bencodez.votingplugin.advancedcore.api.inventory.BInventoryListener$2.run(BInventoryListener.java:96) ~[?:?] at com.bencodez.votingplugin.simpleapi.scheduler.BukkitScheduler.lambda$runTaskAsynchronously$6(BukkitScheduler.java:68) ~[?:?] at com.bencodez.votingplugin.simpleapi.folialib.impl.LegacySpigotImplementation.lambda$runAsync$1(LegacySpigotImplementation.java:58) ~[?:?] at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftTask.run(CraftTask.java:64) ~[patched_1.12.2.jar:git-Paper-1620] at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:52) ~[patched_1.12.2.jar:git-Paper-1620] at com.destroystokyo.paper.ServerSchedulerReportingWrapper.run(ServerSchedulerReportingWrapper.java:22) ~[patched_1.12.2.jar:git-Paper-1620] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144) ~[?:?] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642) ~[?:?] at java.lang.Thread.run(Thread.java:1583) [?:?] Caused by: java.lang.ClassNotFoundException: org.bukkit.Registry ... 12 more [10:15:22 WARN]: [VotingPlugin] Plugin VotingPlugin v7.0 generated an exception while executing task 6007168 java.lang.NoClassDefFoundError: org/bukkit/Registry at com.bencodez.votingplugin.advancedcore.AdvancedCoreConfigOptions.getClickSoundSound(AdvancedCoreConfigOptions.java:304) ~[?:?] at com.bencodez.votingplugin.advancedcore.api.inventory.BInventory.playSound(BInventory.java:648) ~[?:?] at com.bencodez.votingplugin.advancedcore.api.inventory.BInventory.onClick(BInventory.java:507) ~[?:?] at com.bencodez.votingplugin.advancedcore.api.inventory.BInventoryListener$2.run(BInventoryListener.java:96) ~[?:?] at com.bencodez.votingplugin.simpleapi.scheduler.BukkitScheduler.lambda$runTaskAsynchronously$6(BukkitScheduler.java:68) ~[?:?] at com.bencodez.votingplugin.simpleapi.folialib.impl.LegacySpigotImplementation.lambda$runAsync$1(LegacySpigotImplementation.java:58) ~[?:?] at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftTask.run(CraftTask.java:64) ~[patched_1.12.2.jar:git-Paper-1620] at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:52) ~[patched_1.12.2.jar:git-Paper-1620] at com.destroystokyo.paper.ServerSchedulerReportingWrapper.run(ServerSchedulerReportingWrapper.java:22) ~[patched_1.12.2.jar:git-Paper-1620] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144) ~[?:?] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642) ~[?:?] at java.lang.Thread.run(Thread.java:1583) [?:?] Caused by: java.lang.ClassNotFoundException: org.bukkit.Registry ... 12 more
To Reproduce
Steps to reproduce the behavior:

1. Run /vote
2. Click on any item on the GUI
3. Nothing happens
4. The warning above is printed on the console

Expected behavior
Basically opening the ShopGUI for the Voiting Shop option or Displaying the vote sites with the URL option

Screenshots/Configs
This GUI for example:

Additional context
Maybe I should use an older version of the plugin. If its this, please tell me which. (Using Spigot 1.12 API)

[BenCodez]

You'll have to use an older version or the special 1.8 version I have (links on spigot page), but that isn't updated to 7.0