A clean reinstall fixes many stubborn Slack problems — and the good news is your messages are safe in the cloud. Here is how to reinstall without losing anything that matters.
Your Slack account, channels, direct messages and workspaces are tied to your account in the cloud, so they come back the moment you sign in again. What lives only on your device is the local cache — the on-device vault where Slack stores cached messages and downloaded files. That cache is rebuilt automatically, so the only thing worth backing up is any downloaded file you have not saved elsewhere.
In a simple markdown or text file, record each workspace you use, its URL, and the email or method you sign in with. Keep it somewhere safe.
If you have downloaded files in Slack's local vault that are not saved anywhere else, copy them out first. Cloud-synced messages do not need backing up.
Remove Slack through your operating system's normal app-removal process, then restart your computer to clear any locked files.
Download the latest Slack installer from the official site and install it cleanly. A fresh build resolves corruption that was causing your original problem.
Sign in to each workspace from your markdown note. Slack downloads your channels and message history from the cloud automatically, so you are back exactly where you were.
No. Your messages, channels and workspaces live in the cloud against your account, so signing back in restores them. Only locally cached content in Slack's on-device vault is cleared on a clean reinstall, and that is rebuilt automatically from the cloud.
Keep a short markdown note of the workspaces you belong to and the email or sign-in method for each, plus any workspace URLs. That makes signing back in after reinstalling effortless, since Slack itself restores your messages from the cloud.
Usually not, because the local vault is just a cache of cloud data. Back it up only if you have local-only items such as downloaded files you have not saved elsewhere. Otherwise a clean reinstall and sign-in restores everything.
Note your workspaces, then download a fresh official copy and sign back in.