Stellar Data Recovery Knowledge Base (KB) Articles 800

SKB1109

Why is my SD card not getting scanned or detected in Stellar Photo Recovery on Mac?

If your SD card is not getting detected or scanned in Stellar Photo Recovery on Mac, the issue could be related to either a physical lock on the SD card or macOS security settings blocking the device connection. To resolve the issue, follow the steps below: 1. Check the Physical Lock Switch on the SD Card Almost all SD cards have a small mechanical slider on the side for write protection. If the..

Date Published 13 Feb 2026

Total Views 411

SKB1101

How to resolve the Error “Insufficient privileges to complete the operation”?

Issue When selecting Microsoft 365 (M365) as the source or target during migration, users may encounter the error message: “Insufficient privileges to complete the operation” Cause The error appears if the application required for authentication is not properly registered in Microsoft Entra ID (Azure AD) or missing necessary permissions. Resolution To resolve this issue, ensure that applicat..

Date Published 18 Sep 2025

Total Views 387

SKB1098

Error: The server cannot service the request — EWS throttling or temporary unavailability

When performing mailbox operations via Exchange Web Services (EWS), you may encounter the error: "The server cannot service the request". This typically occurs due to throttling or temporary unavailability of the Exchange service (Office 365 or on-premises). Cause EWS Throttling: Office 365 or Exchange on-premises limits the number of concurrent requests per user or application to maintain se..

Date Published 13 Aug 2025

Total Views 374

SKB1104

Error: 503 Server Unavailable During Exchange Online (EWS) Migration

A 503 – Server Unavailable error from Exchange Online is one of the most common failures during EWS migrations, and it always means: Exchange/Office 365 is temporarily refusing your connection because of throttling, overload, or mailbox database movement. This is NOT a permanent failure. It is a temporary block. Causes: 1. Throttling (Most Common) Microsoft heavily throttles EWS: • ..

Date Published 19 Dec 2025

Total Views 372

SKB1105

Underlying Connection Was Closed Error During EWS Migration

Error Message During migration or mailbox processing, you may see the following error: The request failed. The underlying connection was closed: An unexpected error occurred on a send. Problem Description This error is a network-level failure that commonly occurs during EWS migrations, especially when migrating a large number of items or large mailbox data. The connection between the migratio..

Date Published 19 Dec 2025

Total Views 372

SKB1106

Unable to Connect to the Remote Server Error During EWS Migration

Error Message You may encounter the following error during migration or connection attempts: The request failed. Unable to connect to the remote server. Problem Description This error is a network-level failure that occurs before Exchange Online or EWS processes the request. The connection to the remote Exchange service cannot be established at that moment. This is a temporary issue..

Date Published 19 Dec 2025

Total Views 370

SKB1090

How to Provide Impersonate Rights through EAC?

In Exchange environments—whether on-premises or hybrid—certain service accounts or applications (like email migration tools, backup software, or third-party services) may require impersonation rights to access user mailboxes programmatically. This is especially common during mailbox migrations, automated data processing, or account audits. Impersonation allows a designated account to act ..

Date Published 03 Jun 2025

Total Views 358

SKB1100

How to resolve error “Exceeded Message Size Restrictions”?

When migrating mailboxes, you may encounter the error: “Exceeded message size restrictions.” This happens when the source mailbox contains emails larger than the maximum message size allowed at the destination server. If the destination mailbox has stricter size restrictions, the migration cannot proceed for those messages. Cause The maximum message size at the destination server is smaller ..

Date Published 18 Sep 2025

Total Views 356

SKB1092

How to Fix “The SMTP Address Format Is Invalid” Error in Exchange?

If you’re seeing the error “The SMTP address format is invalid” in Exchange, it usually means you’ve entered an email address in the wrong format. This often happens when using a domain-style login instead of a proper email address. Why This Happens Exchange expects a valid SMTP (email) address. When you enter a username like domain\user, it doesn’t qualify as a routable email address..

Date Published 03 Jun 2025

Total Views 341

SKB1099

Request Failed – Remote Server Returned an Error

Applies to: Microsoft Exchange Server (all supported versions) Microsoft 365 Hybrid Exchange environments Summary When connecting to an Exchange server, you may receive the following error message: The request failed. The remote server returned an error. Cause This issue can occur due to one or more of the following reasons: Exchange Server is down or not responding. Network connectiv..

Date Published 13 Aug 2025

Total Views 338