Does the account appear when you click view>folders>all folders?

Yes it does. Thanks so much for your help! -- tralfaz

Just an FYI: accounts don't appear in Unified folders unless they have the same folder names as other accounts. I share your concerns as I also have one account that seems to be hidden. I was glad to assist.

Thanks, I wondered why my Yahoo account doesn't show up in the Unified folders. Unfortunately I don't seem to be able to modify the folders so I guess there's no cure for it. -- tralfaz

If it has an inbox, that should appear in unified folders. I suggest rightclicking tthe unified folder inbox and clicking 'subscribe' to see if Yahoo appears.

I have the same issue. I do see the account in the unified view, when I right-click, however, I get an error message: ExtensionError: Folder not found: account2:// ExtensionError@resource://gre/modules/ExtensionUtils.sys.mjs:48:5 checkDetails@resource:///modules/ExtensionAccounts.sys.mjs:662:13 getFolderDetails@resource:///modules/ExtensionAccounts.sys.mjs:717:10 getFolder@resource:///modules/ExtensionAccounts.sys.mjs:739:14 get@resource:///modules/ExtensionAccounts.sys.mjs:575:33 getMailStoreFromFolderPath@chrome://mboximport/content/mboximport/utils.js:759:60 expMenuDispatcher@chrome://mboximport/content/mboximport/expMenuDispatcher.js:210:47 observe@jar:file:///C:/Users/olafk/AppData/Roaming/Thunderbird/Profiles/9qustxpv.default/extensions/ImportExportToolsNG@cleidigh.kokkini.net.xpi!/chrome/content/mboximport/modules/notifyTools.js:60:40 getAPI/notifyExperiment/<@jar:file:///C:/Users/olafk/AppData/Roaming/Thunderbird/Profiles/9qustxpv.default/extensions/ImportExportToolsNG@cleidigh.kokkini.net.xpi!/api/NotifyTools/implementation.js:50:28 notifyExperiment@jar:file:///C:/Users/olafk/AppData/Roaming/Thunderbird/Profiles/9qustxpv.default/extensions/ImportExportToolsNG@cleidigh.kokkini.net.xpi!/api/NotifyTools/implementation.js:49:20 recvAPICall/result</</<@resource://gre/modules/ExtensionParent.sys.mjs:1223:16 withCallContextData@resource://gre/modules/ExtensionParent.sys.mjs:666:14 recvAPICall/result</<@resource://gre/modules/ExtensionParent.sys.mjs:1222:19 withPendingBrowser@resource://gre/modules/ExtensionParent.sys.mjs:676:26 recvAPICall/result<@resource://gre/modules/ExtensionParent.sys.mjs:1221:24 callAndLog@resource://gre/modules/ExtensionParent.sys.mjs:1172:14 recvAPICall@resource://gre/modules/ExtensionParent.sys.mjs:1220:25 openWindowPrompt@resource://gre/modules/Prompter.sys.mjs:1288:17 openPrompt@resource://gre/modules/Prompter.sys.mjs:1107:12 openPromptSync@resource://gre/modules/Prompter.sys.mjs:1086:10 confirmEx@resource://gre/modules/Prompter.sys.mjs:1539:10 confirmEx@resource://gre/modules/Prompter.sys.mjs:311:14 _promptAuthFailed@resource:///modules/MailAuthenticator.sys.mjs:192:28 promptAuthFailed@resource:///modules/MailAuthenticator.sys.mjs:382:17 _actionAuthResponse@resource:///modules/Pop3Client.sys.mjs:877:42 _onData@resource:///modules/Pop3Client.sys.mjs:356:12 An issue of TB, I have 148.0 windows 32-bit.