Xray is not working properly, how can I resolve this issue? / How do I add another block to Xray
If Xray is not working properly, you might need to add the blocks, the easiest way todo that is typing the command .xray gui, and click the blocks you want xray to use, you can also use .xray add/remove block_name, example: .xray add diamond_ore. Its not suggested that you use fabric api without optifine & optifabric.
Nothing is showing up on my screen in game. / How do I enable the HUD? / How do I access the Click Gui?
If nothing is showing up on your screen, try typing, .toggle hud, in chat, or enable it through the Click Gui. If you can't access the Click Gui, try pressing the RSHIFT (right shift) key. If this does not work, try .bind set click_gui rshift, if that does not work try .bind set click_gui right_shift
Where/how can I get older versions of Inertia Client for like 1.8.9 or 1.13.1?
All versions of Inertia comes packed with ViaVersion(which allows you to conntect to almost any minecraft server without restarting your game) installed by default. All you have todo is load up Inertia Client, go to the multiplayer screen and click the ViaVersion on the top left, you will be prompted with a screen where you can choose any minecraft version 1.8+. Once you select a version, hit escape and join a server for the version you selected.
When using the ViaVersion feature for Inertia Client its suggested you use the newest minecraft version that Inertia Client supports, for example, say Inertia Client supports 1.12.2, 1.13.2, 1.14.4, 1.15.2, 1.16.1, you want to use the 1.16.1 version. Altough it does work on all versions, its just the newest will have less compatibility issues
There is no exact answer but it could be two thing, the first being more likely.
1: OpenJDK, minecraft may be using a OpenJDK version of java, which can cause some problems with Inertia Client. You can fix it by install an offical oracle version of java(its suggest java 8/1.8, as newer versions may crash using Inertia Client). Once you have installed an offical oracle version of java, open the minecraft launcher, edit the installation used to run Inertia Client(it could be forge or fabric), click the more options button and in the java executable path select the java version you just installed, the it should be in the bin folder, probably called javaw. Once you do that save the profile, and try loading Inertia Client.
Try running the minecraft launcher as sudo. (Go to the terminal, type sudo minecraft-launcher)
In chat type .blockesp gui, click the block you would like to add, then a color picker is going to show up, select the color you would like Block ESP you would for that block, click Save then click Back
How do I edit the color of a already added block
In the pause/escape menu click Inertia Options, Color Manger, right click the Block ESP frame, click the block that you are going edit, select a new color then click Save