Sometimes the copy will not work.

[comfyui-wiki]

Most of the time, the copy and paste work normally. But after using the ComfyUI for a while, it suddenly stops working. Refreshing the windows can temporarily solve it.

Here are the console logs:

Screen.Recording.2025-10-31.at.21.43.32.mov

useCopy.ts:29 Uncaught InvalidCharacterError: Failed to execute 'btoa' on 'Window': The string to be encoded contains characters outside of the Latin1 range.
    at HTMLDocument.<anonymous> (useCopy.ts:29:35)
(anonymous) @ useCopy.ts:29
useCopy.ts:29 Uncaught InvalidCharacterError: Failed to execute 'btoa' on 'Window': The string to be encoded contains characters outside of the Latin1 range.

┆Issue is synchronized with this Notion page by Unito

[dosubot]

The intermittent copy/paste failure is caused by an InvalidCharacterError in useCopy.ts when the code tries to use btoa on a string containing Unicode or non-Latin1 characters. This happens because btoa only supports Latin1/ASCII, but the serialized node data can include other characters. Refreshing the browser resets the state, which temporarily resolves the issue.

Recent updates to the codebase confirm this root cause and show that the copy logic still calls btoa directly on the serialized JSON string without encoding it to UTF-8 first, which is the recommended fix (e.g., btoa(unescape(encodeURIComponent(str)))) source.

This issue is known and has been discussed in several threads, with users reporting similar symptoms—copy/paste works for a while, then fails until a refresh, especially when copying nodes with non-ASCII data or after prolonged use. Workarounds include using Firefox, holding Ctrl+C longer, or refreshing the page, but the underlying encoding bug remains source.

If you need a temporary workaround, try to avoid copying nodes with non-ASCII characters, or use Firefox, which seems less affected. For a permanent fix, the copy logic should encode the string as UTF-8 before passing it to btoa.

To reply, just mention @dosu.

---

^{How did I do? Good | Irrelevant | Incorrect | Verbose | Hallucination | Report 🐛 | Other}   

[comfyui-wiki]

Seems this one is happening only on the markdown note node, so it might be because the markdown content contains some characters that can't be copied?

[comfyui-wiki]

esrgan_example (3).json