Update README.md with bugfix instructions

README.md

@@ -1,3 +1,54 @@
+# Help! FoxyProxy Updated and All Settings Are Lost
+
+Using Firefox and you've lost all FoxyProxy settings? FoxyProxy updated from 7.4.2 to 8.2 and you encountered an update bug. You have 3 choices:
+
+## Downgrade to 7.4.2
+
+1. Download https://github.com/foxyproxy/firefox-extension/releases/download/7.4.2/foxyproxy_standard-7.4.2-an+fx.xpi
+2. Click the file; firefox will ask you to install that addon. Confirm.
+3. Go to Firefox settings, addons (about:addons), FoxyProxy, check that it shows version 7.4.2.
+**Important**: On that same page, set "Allow automatic updates" to off, otherwise 8.2 could be installed at any time.
+
+If you upgrade to 8.3, when it is available at https://addons.mozilla.org/en-US/firefox/addon/foxyproxy-standard/ then the bug will be gone.
+
+## Retrieve Settings and Keep 8.2
+
+From [this comment](https://github.com/foxyproxy/browser-extension/issues/45#issuecomment-1838719332):
+
+1. Go to the Options page
+2. Open the Dev Tools (F12)
+3. Go to the Console tab
+4. Type the following and hit ENTER
+
+ browser.storage.sync.get().then(console.log) 
+
+If above has some data, then in the Console tab
+
+1. Type the following and hit ENTER
+
+```js
+browser.storage.sync.get().then(pref => {
+ const data = JSON.stringify(pref, null, 2);
+ const blob = new Blob([data], {type: 'application/json'});
+ browser.downloads.download({
+ url: URL.createObjectURL(blob),
+ filename: 'FoxyProxy_sync.json',
+ saveAs: true,
+ conflictAction: 'uniquify'
+ })
+ .catch(() => {}); 
+});
+```
+
+2. Go to Import Tab -> Import from older versions
+3. Import FoxyProxy_sync.json file that you have saved
+4. Click SAVE to save the data
+
+## Wait For Mozilla to Approve 8.3
+
+It should be available in a few days, but we have no guarantee.
+
+
 # ![FoxyProxy](/src/image/icon.svg) FoxyProxy Browser Extension
 
 [![license](https://img.shields.io/github/license/foxyproxy/browser-extension.svg)](https://github.com/foxyproxy/browser-extension/blob/master/LICENSE)