itzg · itzg · Jun 10, 2023 · Jun 10, 2023
diff --git a/docs/mods-and-plugins/index.md b/docs/mods-and-plugins/index.md
@@ -5,7 +5,8 @@
 By far the easiest way to work with mod and plugins, especially large numbers of them, is to utilize modpacks with [one of the supported mod platforms](../types-and-platforms/index.md).
 
 The following are some supported mod platforms:
-- [Modrinth](../types-and-platforms/mod-platforms/modrinth-modpacks.md)
+
+- [Modrinth](../types-and-platforms/mod-platforms/modrinth-modpacks.md) 
 - [CurseForge](../types-and-platforms/mod-platforms/auto-curseforge.md)
 - [Feed the Beast](../types-and-platforms/mod-platforms/ftb.md)
 

diff --git a/docs/types-and-platforms/mod-platforms/auto-curseforge.md b/docs/types-and-platforms/mod-platforms/auto-curseforge.md
@@ -33,8 +33,7 @@ To manage a CurseForge modpack automatically with upgrade support, pinned or lat
     ```
 
 !!! note
-
-    Be sure to use the appropriate [image tag for the Java version compatible with the modpack](../versions/java.md).
+    Be sure to use the appropriate [image tag for the Java version compatible with the modpack](../../versions/java.md).
 
     Most modpacks require a good amount of memory, so it best to set `MEMORY` to at least "4G" since the default is only 1 GB.
 
@@ -50,7 +49,7 @@ Pass a page URL to the modpack or a specific file with `CF_PAGE_URL` such as the
 
 Instead of a URL, the modpack slug can be provided as `CF_SLUG`. The slug is the short identifier visible in the URL after "/modpacks/", such as
 
-![cf-slug](../img/cf-slug.png)
+![cf-slug](../../img/cf-slug.png)
 
 For example:
 ```
@@ -69,7 +68,7 @@ The latest file will be located and used by default, but if a specific version i
 
 The following shows where to get the URL to the specific file and also shows where the file ID is located:
 
-![cf-file-id](../img/cf-file-id.png)
+![cf-file-id](../../img/cf-file-id.png)
 
 The following examples all refer to version 1.0.7 of ATM8:
 
@@ -92,7 +91,7 @@ Quite often there are mods that need to be excluded, such as ones that did not p
 Mods can be excluded by passing a comma or space delimited list of **project** slugs or IDs via `CF_EXCLUDE_MODS`. Similarly, there are some mods that are incorrectly tagged as client only. For those, pass the **project** slugs or IDs via `CF_FORCE_INCLUDE_MODS`. These lists will be combined with the content of the exclude/include file, if given.
 
 A mod's project ID can be obtained from the right hand side of the project page:
-![cf-project-id](../img/cf-project-id.png)
+![cf-project-id](../../img/cf-project-id.png)
 
 For more complex scenarios, global and per modpack exclusions can be declared in a container-accessible JSON file and referenced with `CF_EXCLUDE_INCLUDE_FILE`. By default, [the file bundled with the image](https://raw.githubusercontent.com/itzg/docker-minecraft-server/master/files/cf-exclude-include.json) will be used, but can be disabled by setting this to an empty string. The schema of this file [is documented here](https://github.com/itzg/mc-image-helper#excludeinclude-file-schema).
 

diff --git a/docs/types-and-platforms/mod-platforms/ftb.md b/docs/types-and-platforms/mod-platforms/ftb.md
@@ -1,8 +1,7 @@
 # Feed the Beast
 
 !!! note
-
-    Requires one of the Ubuntu with Hotspot images listed in [the Java versions section](../versions/java.md).
+    Requires one of the Ubuntu with Hotspot images listed in [the Java versions section](../../versions/java.md).
 
 [Feed the Beast application](https://www.feed-the-beast.com/) modpacks are supported by setting `MOD_PLATFORM` or `TYPE` to "FTBA"
 
@@ -18,7 +17,7 @@ This mod platform type will automatically take care of downloading and installin
   https://www.feed-the-beast.com/modpacks/23-ftb-infinity-evolved-17
                                           ^^
   ```
-- `FTB_MODPACK_VERSION_ID`: optional, the numerical ID of the version to install. If not specified, the latest version will be installed. The "Version ID" can be obtained by hovering over a server file entry and grabbing [this ID in the URL](../img/ftba-version-id-popup.png).
+- `FTB_MODPACK_VERSION_ID`: optional, the numerical ID of the version to install. If not specified, the latest version will be installed. The "Version ID" can be obtained by hovering over a server file entry and grabbing [this ID in the URL](../../img/ftba-version-id-popup.png).
 
 ### Upgrading
 

diff --git a/docs/types-and-platforms/mod-platforms/modrinth-modpacks.md b/docs/types-and-platforms/mod-platforms/modrinth-modpacks.md
@@ -6,10 +6,10 @@ The desired modpack project is specified with the `MODRINTH_PROJECT` environment
 
 - The project "slug", which is located in the URL shown here:
 
-  ![](../img/modrinth-project-slug.drawio.png)
+  ![](../../img/modrinth-project-slug.drawio.png)
 - The project ID, which is located in the bottom of the left panel, shown here
 
-  ![](../img/modrinth-project-id.drawio.png)
+  ![](../../img/modrinth-project-id.drawio.png)
 - The project page URL, such as <https://modrinth.com/modpack/cobblemon-fabric>. As described below, this can further be the page URL of a modpack's version page.
 
 The automatic modpack version resolving can be narrowed in a few ways:
@@ -22,4 +22,4 @@ The selected version can also be narrowed to a particular mod loader by setting
 
 Instead of auto resolving, a specific version of modpack file can be specified by passing the version's page URL to `MODRINTH_PROJECT`, such as <https://modrinth.com/modpack/cobblemon-fabric/version/1.3.2> or by setting `MODRINTH_VERSION` to the version ID or number located in the Metadata section, as shown here
 
-![](../img/modrinth-version-id.drawio.png)
+![](../../img/modrinth-version-id.drawio.png)
diff --git a/docs/types-and-platforms/server-types/bukkit-spigot.md b/docs/types-and-platforms/server-types/bukkit-spigot.md
@@ -1,3 +1,5 @@
+# Bukkit/Spigot
+
 Enable Bukkit/Spigot server mode by adding a `-e TYPE=BUKKIT` or `-e TYPE=SPIGOT` to your command-line.
 
 ```
@@ -15,9 +17,9 @@ If you are hosting your own copy of Bukkit/Spigot you can override the download
 
 You can build spigot from source by adding `-e BUILD_FROM_SOURCE=true`
 
-Plugins can either be managed within the `plugins` subdirectory of the [data directory](../data-directory.md) or you can also [attach a `/plugins` volume](../mods-and-plugins/index.md#optional-plugins-mods-and-config-attach-points). If you add plugins while the container is running, you'll need to restart it to pick those up.
+Plugins can either be managed within the `plugins` subdirectory of the [data directory](../../data-directory.md) or you can also [attach a `/plugins` volume](../../mods-and-plugins/index.md#optional-plugins-mods-and-config-attach-points). If you add plugins while the container is running, you'll need to restart it to pick those up.
 
-[You can also auto-download plugins using `SPIGET_RESOURCES`.](../mods-and-plugins/index.md#auto-downloading-spigotmcbukkitpapermc-plugins-with-spiget)
+[You can also auto-download plugins using `SPIGET_RESOURCES`.](../../mods-and-plugins/spiget.md)
 
 !!! note
 

diff --git a/docs/types-and-platforms/server-types/fabric.md b/docs/types-and-platforms/server-types/fabric.md
@@ -24,4 +24,4 @@ docker run -d -v /path/on/host:/data ... \
     - Provide the path to a custom launcher jar available to the container with `FABRIC_LAUNCHER`, relative to `/data` (such as `-e FABRIC_LAUNCHER=fabric-server-custom.jar`)
     - Provide the URL to a custom launcher jar with `FABRIC_LAUNCHER_URL` (such as `-e FABRIC_LAUNCHER_URL=http://HOST/fabric-server-custom.jar`)
 
-See the [Working with mods and plugins](../mods-and-plugins/index.md) section to set up Fabric mods and configuration.
+See the [Working with mods and plugins](../../mods-and-plugins/index.md) section to set up Fabric mods and configuration.
diff --git a/docs/types-and-platforms/server-types/forge.md b/docs/types-and-platforms/server-types/forge.md
@@ -1,6 +1,6 @@
 Enable [Forge server](http://www.minecraftforge.net/) mode by adding a `-e TYPE=FORGE` to your command-line.
 
-The overall version is specified by `VERSION`, [as described in the section above](../versions/minecraft.md) and will run the recommended Forge version by default. You can also choose to run a specific Forge version with `FORGE_VERSION`, such as `-e FORGE_VERSION=14.23.5.2854`.
+The overall version is specified by `VERSION`, [as described in the section above](../../versions/minecraft.md) and will run the recommended Forge version by default. You can also choose to run a specific Forge version with `FORGE_VERSION`, such as `-e FORGE_VERSION=14.23.5.2854`.
 
 ```
 docker run -d -v /path/on/host:/data \

diff --git a/docs/types-and-platforms/server-types/others.md b/docs/types-and-platforms/server-types/others.md
@@ -6,7 +6,7 @@ Enable SpongeVanilla server mode by adding a `-e TYPE=SPONGEVANILLA` to your com
 By default the container will run the latest `STABLE` version.
 If you want to run a specific version, you can add `-e SPONGEVERSION=1.11.2-6.1.0-BETA-19` to your command-line.
 
-Beware that current [Sponge](https://www.spongepowered.org) `STABLE` versions for Minecraft 1.12 require using [the Java 8 tag](../versions/java.md):
+Beware that current [Sponge](https://www.spongepowered.org) `STABLE` versions for Minecraft 1.12 require using [the Java 8 tag](../../versions/java.md):
 
 ``` shell
 docker run -d -v /path/on/host:/data -e TYPE=SPONGEVANILLA \

diff --git a/docs/types-and-platforms/server-types/paper.md b/docs/types-and-platforms/server-types/paper.md
@@ -8,9 +8,9 @@ By default, the container will run the latest build of [Paper server](https://pa
 
 If you are hosting your own copy of Paper you can override the download URL with `PAPER_DOWNLOAD_URL=<url>`.
 
-If you have attached a host directory to the `/data` volume, then you can install plugins via the `plugins` subdirectory. You can also [attach a `/plugins` volume](../mods-and-plugins/index.md#optional-plugins-mods-and-config-attach-points). If you add plugins while the container is running, you'll need to restart it to pick those up.
+If you have attached a host directory to the `/data` volume, then you can install plugins via the `plugins` subdirectory. You can also [attach a `/plugins` volume](../../mods-and-plugins/index.md#optional-plugins-mods-and-config-attach-points). If you add plugins while the container is running, you'll need to restart it to pick those up.
 
-[You can also auto-download plugins using `SPIGET_RESOURCES`.](../mods-and-plugins/index.md#auto-downloading-spigotmcbukkitpapermc-plugins-with-spiget)
+[You can also auto-download plugins using `SPIGET_RESOURCES`.](../../mods-and-plugins/spiget.md)
 
 ## Alternatives
 
@@ -57,9 +57,9 @@ By default, the container will run the latest build of [Folia server](https://pa
 
 If you are hosting your own copy of Folia you can override the download URL with `FOLIA_DOWNLOAD_URL=<url>`.
 
-If you have attached a host directory to the `/data` volume, then you can install plugins via the `plugins` subdirectory. You can also [attach a `/plugins` volume](../mods-and-plugins/index.md#optional-plugins-mods-and-config-attach-points). If you add plugins while the container is running, you'll need to restart it to pick those up.
+If you have attached a host directory to the `/data` volume, then you can install plugins via the `plugins` subdirectory. You can also [attach a `/plugins` volume](../../mods-and-plugins/index.md#optional-plugins-mods-and-config-attach-points). If you add plugins while the container is running, you'll need to restart it to pick those up.
 
-[You can also auto-download plugins using `SPIGET_RESOURCES`.](../mods-and-plugins/index.md#auto-downloading-spigotmcbukkitpapermc-plugins-with-spiget)
+[You can also auto-download plugins using `SPIGET_RESOURCES`.](../../mods-and-plugins/spiget.md)
 
 !!! note
     The Folia type inherits from the Paper type. Paper's variables will override the Folia ones.
diff --git a/docs/types-and-platforms/server-types/quilt.md b/docs/types-and-platforms/server-types/quilt.md
@@ -24,4 +24,4 @@ docker run -d -v /path/on/host:/data ... \
     - Provide the path to a custom launcher jar available to the container with `QUILT_LAUNCHER`, relative to `/data` (such as `-e QUILT_LAUNCHER=quilt-server-custom.jar`)
     - Provide the URL to a custom launcher jar with `QUILT_LAUNCHER_URL` (such as `-e QUILT_LAUNCHER_URL=http://HOST/quilt-server-custom.jar`)
 
-See the [Working with mods and plugins](../mods-and-plugins/index.md) section to set up Quilt mods and configuration.
+See the [Working with mods and plugins](../../mods-and-plugins/index.md) section to set up Quilt mods and configuration.
diff --git a/docs/versions/java.md b/docs/versions/java.md
@@ -4,6 +4,13 @@
 
     For Forge versions less than 1.18, you _must_ use the `java8-multiarch` (or other java8) image tag.
 
+    In general, if you see the following line in a server startup failure, then it means you need to be using Java 8 instead of the latest image Java version:
+
+    ```
+    Caused by: java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader 
+       cannot be cast to class java.net.URLClassLoader
+    ```
+
 When using the image `itzg/minecraft-server` without a tag, the `latest` image tag is implied from the table below. To use a different version of Java, please use an alternate tag to run your Minecraft server container.
 
 | Tag name          | Java version | Linux  | JVM Type    | Architecture      |
@@ -23,7 +30,7 @@ When using the image `itzg/minecraft-server` without a tag, the `latest` image t
 | java17-graalvm-ce | 17           | Oracle | GraalVM CE  | amd64,arm64       |
 | java17-alpine     | 17           | Alpine | Hotspot     | amd64             |
 | java20-alpine     | 19           | Alpine | Hotspot     | amd64             |
-| java20            | 19           | Ubuntu | Hotspot     | amd64,arm64 |
+| java20            | 19           | Ubuntu | Hotspot     | amd64,arm64       |
 
 For example, to use Java version 8 on any supported architecture: