I am not a developer, just a hobbyist.

I installed the Cardano Node (1.33.0-win64) so that I could point my Nami Wallet Browser Extension to it, rather than the web server node Nami points to by default. Ever since installing the node, I get browser errors that reference the Cardano Node and "WebAssembly.instantiateStreaming" (full console error from dev tools below). Just visiting websites is all it takes to get the errors.

Can someone help me learn more about this, and perhaps point me in the direction to a solution? I could just uninstall the node, but I want to solve the issue.

Thank you!

cardano_serialization_lib.js:13074 GET https://www.google.com/wasm/csl-v10.0.4.wasm 404 cardano_serialization_lib_init @ cardano_serialization_lib.js:13074 (anonymous) @ CardanoSerializationLib.ts:11 (anonymous) @ CardanoSerializationLib.ts:15 (anonymous) @ dom-script.js:27 (anonymous) @ dom-script.js:27 cardano_serialization_lib.js:12883 WebAssembly.instantiateStreaming failed because your server does not serve wasm with application/wasm MIME type. Falling back to WebAssembly.instantiate which is slower. Original error: TypeError: Failed to execute 'compile' on 'WebAssembly': HTTP status code is not ok load @ cardano_serialization_lib.js:12883 await in load (async) cardano_serialization_lib_init @ cardano_serialization_lib.js:13079 await in cardano_serialization_lib_init (async) (anonymous) @ CardanoSerializationLib.ts:11 (anonymous) @ CardanoSerializationLib.ts:15 (anonymous) @ dom-script.js:27 (anonymous) @ dom-script.js:27

1 Answer 1


Your browser or extension is trying to get the wasm code.

Your error shows GET https://www.google.com/wasm/csl-v10.0.4.wasm 404

The 404 result means 'not found'.

I found this reference: https://github.com/Emurgo/cardano-serialization-lib/issues/398

Do you have Eternl wallet extension installed in your browser? Seems that it is using the wasm URL above and failing, so best to disable Eternl wallet extension and try again.

Keep in mind that browser extensions inject their code into every page that you visit, so if one extension is not working correctly the impact will be felt on every page that you visit.

  • I think this issue is being tracked on github.com/ccwalletio/tracker/issues/119. It is a pretty major bug introduced by this Wallet Browser Extension. Commented May 12, 2022 at 1:44
  • I disabled Eternl and that totally eliminated the error message! I thought it was the node this whole time. Thank you so much.
    – gene
    Commented May 13, 2022 at 3:21

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