diff --git a/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/FinTsClient.kt b/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/FinTsClient.kt
index 26c09cd4..f7a5435f 100644
--- a/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/FinTsClient.kt
+++ b/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/FinTsClient.kt
@@ -25,6 +25,7 @@ import net.dankito.banking.fints.transactions.IAccountTransactionsParser
 import net.dankito.banking.fints.transactions.Mt940AccountTransactionsParser
 import net.dankito.banking.fints.util.IBase64Service
 import net.dankito.banking.fints.util.PureKotlinBase64Service
+import net.dankito.utils.multiplatform.log.Logger
 import net.dankito.utils.multiplatform.log.LoggerFactory
 import net.dankito.banking.fints.webclient.IWebClient
 import net.dankito.banking.fints.webclient.KtorWebClient
@@ -58,6 +59,14 @@ open class FinTsClient(
     open val messageLogWithoutSensitiveData: List<MessageLogEntry>
             get() = messageLogCollector.messageLogWithoutSensitiveData
 
+    protected open val messageLogAppender: IMessageLogAppender = object : IMessageLogAppender {
+
+        override fun logError(message: String, e: Exception?, logger: Logger?, bank: BankData?) {
+            messageLogCollector.logError(message, e, logger, bank)
+        }
+
+    }
+
 
     /**
      * Retrieves information about bank (e.g. supported HBCI versions, FinTS server address,
@@ -756,14 +765,14 @@ open class FinTsClient(
 
                 return responseParser.parse(decodedResponse)
             } catch (e: Exception) {
-                log.error(e) { "Could not decode responseBody:\r\n'$responseBody'" }
+                logError("Could not decode responseBody:\r\n'$responseBody'", dialogContext, e)
 
                 return BankResponse(false, errorMessage = e.getInnerExceptionMessage())
             }
         }
         else {
             val bank = dialogContext.bank
-            log.error(webResponse.error) { "Request to $bank (${bank.finTs3ServerAddress}) failed" }
+            logError("Request to $bank (${bank.finTs3ServerAddress}) failed", dialogContext, webResponse.error)
         }
 
         return BankResponse(false, errorMessage = webResponse.error?.getInnerExceptionMessage())
@@ -788,6 +797,10 @@ open class FinTsClient(
         messageLogCollector.addMessageLog(message, type, dialogContext.bank)
     }
 
+    protected open fun logError(message: String, dialogContext: DialogContext, e: Exception?) {
+        messageLogAppender.logError(message, e, log, dialogContext.bank)
+    }
+
 
     protected open fun handleMayRequiresTan(response: BankResponse, dialogContext: DialogContext, callback: (BankResponse) -> Unit) { // TODO: use response from DialogContext
 
diff --git a/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/log/MessageLogCollector.kt b/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/log/MessageLogCollector.kt
index c8d9aa45..5ad69a71 100644
--- a/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/log/MessageLogCollector.kt
+++ b/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/log/MessageLogCollector.kt
@@ -3,6 +3,7 @@ package net.dankito.banking.fints.log
 import net.dankito.banking.fints.model.BankData
 import net.dankito.banking.fints.model.MessageLogEntry
 import net.dankito.banking.fints.model.MessageLogEntryType
+import net.dankito.utils.multiplatform.log.Logger
 import net.dankito.utils.multiplatform.log.LoggerFactory
 import net.dankito.utils.multiplatform.Date
 import net.dankito.utils.multiplatform.getInnerExceptionMessage
@@ -39,7 +40,27 @@ open class MessageLogCollector {
     }
 
 
-    protected open fun removeSensitiveDataFromMessage(message: String, bank: BankData): String {
+    open fun logError(message: String, e: Exception? = null, logger: Logger? = null, bank: BankData?) {
+        val prettyPrintMessage = prettyPrintHbciMessage(message)
+
+        val loggerToUse = logger ?: log
+        if (e != null) {
+            loggerToUse.error(e) { prettyPrintMessage }
+        }
+        else {
+            loggerToUse.error(prettyPrintMessage)
+        }
+
+        // TODO: what to do when bank is not set?
+        messageLog.add(MessageLogEntry(prettyPrintMessage, MessageLogEntryType.Error, Date(), bank))
+    }
+
+
+    protected open fun removeSensitiveDataFromMessage(message: String, bank: BankData?): String {
+        if (bank == null) {
+            return message
+        }
+
         var prettyPrintMessageWithoutSensitiveData = message
             .replace(bank.customerId, "<customer_id>")
             .replace("+" + bank.pin, "+<pin>")
diff --git a/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/model/MessageLogEntry.kt b/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/model/MessageLogEntry.kt
index 942aebf5..8ba02beb 100644
--- a/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/model/MessageLogEntry.kt
+++ b/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/model/MessageLogEntry.kt
@@ -7,7 +7,7 @@ open class MessageLogEntry(
     open val message: String,
     open val type: MessageLogEntryType,
     open val time: Date,
-    open val bank: BankData
+    open val bank: BankData?
 ) {
 
     override fun toString(): String {
diff --git a/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/model/MessageLogEntryType.kt b/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/model/MessageLogEntryType.kt
index b64a76c6..d658768e 100644
--- a/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/model/MessageLogEntryType.kt
+++ b/fints4k/src/commonMain/kotlin/net/dankito/banking/fints/model/MessageLogEntryType.kt
@@ -5,6 +5,8 @@ enum class MessageLogEntryType {
 
     Sent,
 
-    Received
+    Received,
+
+    Error
 
 }
\ No newline at end of file
diff --git a/ui/BankingUiCommon/src/commonMain/kotlin/net/dankito/banking/ui/model/MessageLogEntryType.kt b/ui/BankingUiCommon/src/commonMain/kotlin/net/dankito/banking/ui/model/MessageLogEntryType.kt
index a2013687..733426cf 100644
--- a/ui/BankingUiCommon/src/commonMain/kotlin/net/dankito/banking/ui/model/MessageLogEntryType.kt
+++ b/ui/BankingUiCommon/src/commonMain/kotlin/net/dankito/banking/ui/model/MessageLogEntryType.kt
@@ -5,6 +5,8 @@ enum class MessageLogEntryType {
 
     Sent,
 
-    Received
+    Received,
+
+    Error
 
 }
\ No newline at end of file
diff --git a/ui/BankingUiCommon/src/commonMain/kotlin/net/dankito/banking/ui/presenter/BankingPresenter.kt b/ui/BankingUiCommon/src/commonMain/kotlin/net/dankito/banking/ui/presenter/BankingPresenter.kt
index d84958de..027d9d26 100644
--- a/ui/BankingUiCommon/src/commonMain/kotlin/net/dankito/banking/ui/presenter/BankingPresenter.kt
+++ b/ui/BankingUiCommon/src/commonMain/kotlin/net/dankito/banking/ui/presenter/BankingPresenter.kt
@@ -799,12 +799,17 @@ open class BankingPresenter(
         })
 
         return logEntries.map { entry ->
-            MessageLogEntryDateFormatter.format(entry.time) + " " + getMessageLogPrefix(entry) + "\r\n" + entry.bank.bankCode + " " + entry.message
+            MessageLogEntryDateFormatter.format(entry.time) + " " + entry.bank.bankCode + " " + getMessageLogPrefix(entry) + "\r\n" + entry.message
         }
     }
 
     protected open fun getMessageLogPrefix(entry: MessageLogEntry): String {
-        return "${if (entry.type == MessageLogEntryType.Sent) "Sending" else "Received"} message:" // TODO: translate
+        // TODO: translate
+        return when (entry.type) {
+            MessageLogEntryType.Sent -> "Sending message"
+            MessageLogEntryType.Received -> "Received message"
+            MessageLogEntryType.Error -> "Error"
+        }
     }
 
 
diff --git a/ui/fints4kBankingClient/src/commonMain/kotlin/net/dankito/banking/fints4kBankingClient.kt b/ui/fints4kBankingClient/src/commonMain/kotlin/net/dankito/banking/fints4kBankingClient.kt
index acaa8c6a..80f6aefc 100644
--- a/ui/fints4kBankingClient/src/commonMain/kotlin/net/dankito/banking/fints4kBankingClient.kt
+++ b/ui/fints4kBankingClient/src/commonMain/kotlin/net/dankito/banking/fints4kBankingClient.kt
@@ -61,6 +61,7 @@ open class fints4kBankingClient(
         return when (type) {
             MessageLogEntryType.Sent -> net.dankito.banking.ui.model.MessageLogEntryType.Sent
             MessageLogEntryType.Received -> net.dankito.banking.ui.model.MessageLogEntryType.Received
+            MessageLogEntryType.Error -> net.dankito.banking.ui.model.MessageLogEntryType.Error
         }
     }