２回目のログ　※例のアドオンのエラーはでませんでした。

12:57:17.390 ExtensionParent.sys.mjs:1805
Message manager was disconnected before receiving Extension:ExtensionViewLoaded
    observer resource://gre/modules/ExtensionParent.sys.mjs:1805
    _releaseBrowser resource://gre/modules/ExtensionParent.sys.mjs:1502
    shutdown resource://gre/modules/ExtensionParent.sys.mjs:1497
    shutdown chrome://extensions/content/parent/ext-backgroundPage.js:145
    onShutdown chrome://extensions/content/parent/ext-backgroundPage.js:627
    ExtensionAPI resource://gre/modules/ExtensionCommon.sys.mjs:357
    wrapper resource://gre/modules/ExtensionCommon.sys.mjs:301
    emit resource://gre/modules/ExtensionCommon.sys.mjs:328
    emit resource://gre/modules/Extension.sys.mjs:2867
    shutdown resource://gre/modules/Extension.sys.mjs:3643
    AsyncFunctionNext self-hosted:852

12:57:17.393 2 ExtensionParent.sys.mjs:1285 ２回発生していました
WebExtension context not found!
    getContextById resource://gre/modules/ExtensionParent.sys.mjs:1285
    recvAddListener resource://gre/modules/ExtensionParent.sys.mjs:1183
    _recv resource://gre/modules/ConduitsChild.sys.mjs:77
    receiveMessage resource://gre/modules/ConduitsParent.sys.mjs:453

12:57:17.556 Policies.sys.mjs:1584
Policies.jsm: Installation failed - ERROR_FILE_ACCESS - {url}

12:57:17.864 DBViewWrapper.jsm:88
Uncaught Error: Component returned failure code: 0x80550005 [nsIMsgFolder.updateFolder]
    updateFolderAndNotifyOnLoad resource:///modules/DBViewWrapper.jsm:88
    open resource:///modules/DBViewWrapper.jsm:812
    _onSelect chrome://messenger/content/about3Pane.js:2578
    handleEvent chrome://messenger/content/about3Pane.js:1597
    <anonymous> chrome://messenger/content/about3Pane.js:128

    updateFolderAndNotifyOnLoad resource:///modules/DBViewWrapper.jsm:88
    open resource:///modules/DBViewWrapper.jsm:812
    _onSelect chrome://messenger/content/about3Pane.js:2578
    handleEvent chrome://messenger/content/about3Pane.js:1597
    <匿名> chrome://messenger/content/about3Pane.js:128
    AsyncFunctionNext self-hosted:852

12:57:17.905 NativeMessaging.sys.mjs:174
this.proc is null
    _startRead resource://gre/modules/NativeMessaging.sys.mjs:174
    readPromise resource://gre/modules/NativeMessaging.sys.mjs:187

12:57:28.539 IndexMsg.jsm:662:17
gloda.index_msg: Problem entering folder: 受信トレイ, skipping. Error was: undefined:629: [Exception... "Component returned failure code: 0x8055000a [nsIMsgLocalMailFolder.getDatabaseWithReparse]" nsresult: "0x8055000a (<unknown>)" location: "JS frame :: resource:///modules/gloda/IndexMsg.jsm :: _indexerEnterFolder :: line 629" data: no]
    _indexerEnterFolder resource:///modules/gloda/IndexMsg.jsm:662
    _worker_folderIndex resource:///modules/gloda/IndexMsg.jsm:1389
    workBatch resource:///modules/gloda/GlodaIndexer.jsm:1071
    callbackDriver resource:///modules/gloda/GlodaIndexer.jsm:855
    _wrapCallbackDriver resource:///modules/gloda/GlodaIndexer.jsm:788
    handleCompletion resource:///modules/gloda/GlodaDatastore.jsm:65

12:57:28.540 GlodaIndexer.jsm:1159:21
gloda.indexer: Problem during [job:folder id:1 items:0 offset:0 goal:null], bailing: Error: Component returned failure code: 0x8055000a [nsIMsgLocalMailFolder.getDatabaseWithReparse]
    _indexerEnterFolder resource:///modules/gloda/IndexMsg.jsm:629
    _worker_folderIndex resource:///modules/gloda/IndexMsg.jsm:1389
    workBatch resource:///modules/gloda/GlodaIndexer.jsm:1071
    callbackDriver resource:///modules/gloda/GlodaIndexer.jsm:855
    _wrapCallbackDriver resource:///modules/gloda/GlodaIndexer.jsm:788
    handleCompletion resource:///modules/gloda/GlodaDatastore.jsm:65

12:58:19.797 ext-mail.js:2555
: Component returned failure code: 0x80550005 [nsIMsgFolder.msgDatabase]
    findNewMessages chrome://messenger/content/parent/ext-mail.js:2555
    onFolderIntPropertyChanged chrome://messenger/content/parent/ext-mail.js:2522
    _actionHandleMessage resource:///modules/Pop3Client.jsm:1278
    _actionRetrResponse resource:///modules/Pop3Client.jsm:1438
    read resource:///modules/LineReader.jsm:65
    _actionRetrResponse resource:///modules/Pop3Client.jsm:1404
    _onData resource:///modules/Pop3Client.jsm:356
    AsyncFunctionNext self-hosted:852

12:58:19.874 MailNotificationManager.jsm:425
Component returned failure code: 0x80550005 [nsIMsgFolder.msgDatabase]

_________________
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:128.0) Gecko/20100101 Firefox/128.0

３回目のログ　※例のアドオンのエラーはでませんでした。

13:12:42.191 Policies.sys.mjs:1584
Policies.jsm: Installation failed - ERROR_FILE_ACCESS - {url}

13:12:42.695 DBViewWrapper.jsm:88
Uncaught Error: Component returned failure code: 0x80550005 [nsIMsgFolder.updateFolder]
    updateFolderAndNotifyOnLoad resource:///modules/DBViewWrapper.jsm:88
    open resource:///modules/DBViewWrapper.jsm:812
    _onSelect chrome://messenger/content/about3Pane.js:2578
    handleEvent chrome://messenger/content/about3Pane.js:1597
    <anonymous> chrome://messenger/content/about3Pane.js:128

    updateFolderAndNotifyOnLoad resource:///modules/DBViewWrapper.jsm:88
    open resource:///modules/DBViewWrapper.jsm:812
    _onSelect chrome://messenger/content/about3Pane.js:2578
    handleEvent chrome://messenger/content/about3Pane.js:1597
    <匿名> chrome://messenger/content/about3Pane.js:128
    AsyncFunctionNext self-hosted:852

13:12:42.905 NativeMessaging.sys.mjs:174
this.proc is null
    _startRead resource://gre/modules/NativeMessaging.sys.mjs:174
    readPromise resource://gre/modules/NativeMessaging.sys.mjs:187
    read resource:///modules/LineReader.jsm:60
    _actionListResponse resource:///modules/Pop3Client.jsm:1066
    _onData resource:///modules/Pop3Client.jsm:356
    AsyncFunctionNext self-hosted:852

13:12:53.523 IndexMsg.jsm:662:17
gloda.index_msg: Problem entering folder: 受信トレイ, skipping. Error was: undefined:629: [Exception... "Component returned failure code: 0x8055000a [nsIMsgLocalMailFolder.getDatabaseWithReparse]" nsresult: "0x8055000a (<unknown>)" location: "JS frame :: resource:///modules/gloda/IndexMsg.jsm :: _indexerEnterFolder :: line 629" data: no]
    _indexerEnterFolder resource:///modules/gloda/IndexMsg.jsm:662
    _worker_folderIndex resource:///modules/gloda/IndexMsg.jsm:1389
    workBatch resource:///modules/gloda/GlodaIndexer.jsm:1071
    callbackDriver resource:///modules/gloda/GlodaIndexer.jsm:855
    _timerCallbackDriver resource:///modules/gloda/GlodaIndexer.jsm:781

13:12:53.523 GlodaIndexer.jsm:1159:21
gloda.indexer: Problem during [job:folder id:1 items:0 offset:0 goal:null], bailing: Error: Component returned failure code: 0x8055000a [nsIMsgLocalMailFolder.getDatabaseWithReparse]
    _indexerEnterFolder resource:///modules/gloda/IndexMsg.jsm:629
    _worker_folderIndex resource:///modules/gloda/IndexMsg.jsm:1389
    workBatch resource:///modules/gloda/GlodaIndexer.jsm:1071
    callbackDriver resource:///modules/gloda/GlodaIndexer.jsm:855
    _timerCallbackDriver resource:///modules/gloda/GlodaIndexer.jsm:781

13:13:41.769 ext-mail.js:2555
: Component returned failure code: 0x80550005 [nsIMsgFolder.msgDatabase]
    findNewMessages chrome://messenger/content/parent/ext-mail.js:2555
    onFolderIntPropertyChanged chrome://messenger/content/parent/ext-mail.js:2522
    _actionHandleMessage resource:///modules/Pop3Client.jsm:1278
    _actionRetrResponse resource:///modules/Pop3Client.jsm:1438
    read resource:///modules/LineReader.jsm:65
    _actionRetrResponse resource:///modules/Pop3Client.jsm:1404
    _onData resource:///modules/Pop3Client.jsm:356
    AsyncFunctionNext self-hosted:852

13:13:41.846 MailNotificationManager.jsm:425
Component returned failure code: 0x80550005 [nsIMsgFolder.msgDatabase]

13:33:10.368 ext-mail.js:2555
: Component returned failure code: 0x80550005 [nsIMsgFolder.msgDatabase]
findNewMessages chrome://messenger/content/parent/ext-mail.js:2555
onFolderIntPropertyChanged chrome://messenger/content/parent/ext-mail.js:2527
_actionHandleMessage resource:///modules/Pop3Client.jsm:1278
_actionRetrResponse resource:///modules/Pop3Client.jsm:1438
read resource:///modules/LineReader.jsm:65
_actionRetrResponse resource:///modules/Pop3Client.jsm:1404
_onData resource:///modules/Pop3Client.jsm:356
AsyncFunctionNext self-hosted:852

13:33:10.442 MailNotificationManager.jsm:425
Component returned failure code: 0x80550005 [nsIMsgFolder.msgDatabase]

14:13:10.393 ext-mail.js:2555
: Component returned failure code: 0x80550005 [nsIMsgFolder.msgDatabase]
findNewMessages chrome://messenger/content/parent/ext-mail.js:2555
onFolderIntPropertyChanged chrome://messenger/content/parent/ext-mail.js:2527
_actionHandleMessage resource:///modules/Pop3Client.jsm:1278
_actionRetrResponse resource:///modules/Pop3Client.jsm:1438
read resource:///modules/LineReader.jsm:65
_actionRetrResponse resource:///modules/Pop3Client.jsm:1404
_onData resource:///modules/Pop3Client.jsm:356
AsyncFunctionNext self-hosted:852

14:13:10.427 MailNotificationManager.jsm:425
Component returned failure code: 0x80550005 [nsIMsgFolder.msgDatabase]

_________________
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:128.0) Gecko/20100101 Firefox/128.0

まっぱ さん、ありがとうございます。


これは、「１回目のログ」ということでしょうか。
そして「例のエラー」は下記のどちらでしょうか。

• parsingFolderFailed=他の処理で使用されているため %S フォルダーを開けませんでした。他の操作が終了するのを待ってから再度フォルダーを選択してください。
• pop3ServerBusy=アカウント %S は処理中です。受信処理が終了するまでしばらくお待ちください。

1回目、2回目、3回目のログをWinMergeで比較した画像を添付しておきます。
【追記】
Thunderbird のバージョンは 115.13.0 それとも 128.0.1esr でしょうか。（ソースコードの行数で見るので）

_________________
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:128.0) Gecko/20100101 Firefox/128.0

EarlgreyTea さま

ご質問に回答します。

例のエラーは「parsingFolderFailed=他の処理で使用されているため %S フォルダーを開けませんでした。他の操作が終了するのを待ってから再度フォルダーを選択してください」になります。
このエラーが発生したログは、１回目のログになります。

バージョンは115.13.0でした。

よろしくお願いいたします。

_________________
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:128.0) Gecko/20100101 Firefox/128.0