"“Failed to execute Script timed out”
This time-out error occurs when the [script] is ‘too big’ and Minecraft (WorldEdit really) will abort the script if it is taking too long.
By default the setting is "scripting-timeout=3000" ms (= 3 seconds). Try increasing this setting to 10000 (10k) to enable you to [run bigger / longer scripts] (change in “…\.minecraft\config\worldedit\worldedit.properties”).
On my old / slow PC (with “scripting-timeout=10000" / 10k), ‘too big’ is about 200,000 blocks (e.g. L=2000 x H=10 x W=10 = 200k).
If the script aborts, it may look like it worked but as you go along you may find it didn’t complete properly. You can do an “/undo” and run the script again but make the [script] shorter / smaller."
From my tunnel.js: "I have created a craftscript (tunnel.js) that makes a tunnel in Minecraft / WorldEdit.
If you would like to access / use it (freely of course), the script and instructions are located at bmcbeth.com/tunnel"