When I first started to use codex around one month ago, when i wanted to add a file in the chat, i was simply clicking on the +file button at the bottom left and I was adding the file. Now, If I do so, if a click on a file from that + button, codex stall, and i have to close and reopen the chat to continuing use it. To add a file now I have to copy the file by right click on the file copying it, and paste+V in the chat window, and the files are added without stalling. (I’m a windows user). I reporting this bug in case you are yet not awere of it and want to go to fix it.
Welcome to the forum!
You are welcome to discuss Codex issues on the forum, however the official place to report and track them is the GitHub issue tracker for OpenAI Codex.
I had ChatGPT look for the closest related issue which lead to this open issue
If that issue matches your problem, consider adding a 
reaction on the GitHub issue page itself, not just on the forum topic, as reactions on GitHub help the developers gauge impact and prioritize work.
If it is not the same issue, try searching the existing GitHub issues for a closer match. If you cannot find one, then open a new issue with as much detail as possible.
Thanks for reporting this, @luigi.mazzei. The file attachment button freezing Codex on Windows definitely sounds disruptive.
And thanks, @EricGT, for linking the existing GitHub report.
@luigi.mazzei, please also create a support ticket by emailing support@openai.com so the case can be referenced internally. Include the exact reproduction steps, error timestamp, affected organization or workspace, expected versus actual behavior, plan tier, and a screenshot or screen recording if possible.
Once done, kindly drop the case ID here so our team can help monitor.
-Mark G.