Games Tictactoe works perfectly fine in Editor, but having trouble when building to WebGL

Made a simple tic tac toe game as my first game! It works perfectly fine in the Unity editor, but for some reason when I try to build it to WebGL it gives me the error:

Uncaught TypeError: Cannot read property '14' of undefined
at _glVertexAttribIPointer (blob:https://phypoh.github.io/51ae6a9f-1947-4d7a-aaaa-4b0fc6df7c97:8)
at /tictactoe/<anonymous>:wasm-function[6095]:0x1f7227
at /tictactoe/<anonymous>:wasm-function[6091]:0x1f6ac6
at /tictactoe/<anonymous>:wasm-function[6090]:0x1f676d
at /tictactoe/<anonymous>:wasm-function[5916]:0x1ed143
at /tictactoe/<anonymous>:wasm-function[14523]:0x5910d3
at /tictactoe/<anonymous>:wasm-function[14521]:0x590caa
at /tictactoe/<anonymous>:wasm-function[14469]:0x5874e6
at /tictactoe/<anonymous>:wasm-function[10109]:0x3be578
at /tictactoe/<anonymous>:wasm-function[10082]:0x3bda75
at /tictactoe/<anonymous>:wasm-function[9814]:0x39b9be
at /tictactoe/<anonymous>:wasm-function[9814]:0x39b9d3
at /tictactoe/<anonymous>:wasm-function[9806]:0x39abb6
at /tictactoe/<anonymous>:wasm-function[9800]:0x399233
at dynCall_v (/tictactoe/<anonymous>:wasm-function[36565]:0x9b4eb7)
at Object.dynCall_v (blob:https://phypoh.github.io/51ae6a9f-1947-4d7a-aaaa-4b0fc6df7c97:8)
at browserIterationFunc (blob:https://phypoh.github.io/51ae6a9f-1947-4d7a-aaaa-4b0fc6df7c97:8)
at Object.runIter (blob:https://phypoh.github.io/51ae6a9f-1947-4d7a-aaaa-4b0fc6df7c97:8)
at Browser_mainLoop_runner (blob:https://phypoh.github.io/51ae6a9f-1947-4d7a-aaaa-4b0fc6df7c97:8)

Anyone able to help?

My Github Repo is https://github.com/phypoh/tictactoe and the corresponding game should be (but isn't working) on https://phypoh.github.io/tictactoe/