Mend Outlook Error Unable to Complete This Request

“Hi there, since from 2 days whenever I try to send emails from my Outlook, I receive an error ‘Sorry, Outlook was unable to complete this request’. I didn’t understand why this error is coming. I tried every possible way to fix this issue but was out of luck. Can anyone suggest me good suggestion to fix the above Outlook error? Please help.”

Microsoft Outlook is a well known email client used on multiple OS platforms. This amazing mail application allows users to work with their Outlook mail accounts in both online and offline modes. While working online, Outlook saves all mail attributes in PST file format; and Outlook users who prefer offline mode working will have to create OST file in association with Exchange Server, to which Outlook is connected. Unfortunately, Outlook users encounter varieties of errors that spoil the working of Outlook and create problems. One such error is ‘Outlook unable to complete the request’.

“Outlook wasn’t able to complete this request error”

When user tries to send / receive emails or saves newly created contact, appointment, task, etc. this error may get displayed on Outlook. The above error can also be displayed as “Could not complete the operation. One or more parameter values are not valid”. This error generally occurs when Auto-complete list is corrupt on Outlook. This is a list of all operations that user performs in Outlook and this list can get corrupt due to problems with PST file. The possible reasons behind Outlook PST file damage or corruption are:

  • Malicious malware infection to PST file
  • Malfunctioning of Outlook due to incorrect configuration
  • SRS (Send Receive Settings) file corruption
  • Errors while upgrading Outlook from one version to another version
  • Frequent termination of Outlook in abnormal way or due to sudden power surges
  • Presence of bad media spots on hard drive where PST file is saved
  • Incorrect Outlook preference settings or missing of .dll files of Outlook

In all these instances, due to PST file damage, Auto-complete list can get corrupt and this may render Outlook was unable to complete this request error. However, there is a simple method to fix corrupt Autocomplete list on Outlook as explained below:

  • For Outlook 2010 version - Open Run and type outlook.exe /cleanautocompletecache and press OK. Or you can just open Outlook, go to File -> Options -> Mail dialog and click on Empty Auto-complete list
  • For Outlook 2007 and 2003 versions - Delete NK2 file from the drive located at %USERPROFILE%\Application Data\Microsoft\Outlook

If these methods doesn’t support in fixing Outlook was unable to complete this request error, then uses can try using inbox repair tool named Scanpst.exe to fix errors in Outlook PST file; but when scanpst.exe fails to repair PST file due to severity of PST file problem, then only way is to employ third party PST repair software like Yodot Outlook PST Repair to resolve the error.

Software to repair error Outlook wasn’t able to complete this request:

Yodot Outlook PST Repair tool involves all advanced strategies to fix PST file that shows error and does not work successfully. This software is able to repair Outlook PST file that is corrupt or damaged after oversize, virus intrusion, invalid location and other issues with utmost ease. The software can effectively mend PST file created on Outlook 2000, 2003, 2007, 2010 and 2013 versions. This tool can even repair corrupt Outlook OST file that shows errors like OST file cannot be accessed, invalid OST file, etc. This program can be utilized to repair PST file on Windows 8, Windows 7, Windows Vista, Windows XP, Windows Server 2008 and 2003 OS based computers and laptops with ease.

Procedural steps to make use of PST repair tool:

  • Download the software on your Windows computer where error showing PST file reside
  • Install the software and run it from Start menu or from desktop shortcut icon
  • In main screen, click on ‘Open PST File’; if you know exact location of .pst file on system drive
  • Else, if you don’t know location of PST file click on ‘Find PST File’ option
  • Or if Outlook has multiple profiles, then click on ‘Select Outlook profile’ option to choose particular PST file
  • After choosing required PST file, select the mode of scanning between Normal Scan and Smart Scan options
  • Then, mention destination location where you wish to save repaired PST file at the end of process and click on Repair button
  • After completion of repair process, fixed PST file will be accessible from mentioned destination location

Important Note:

  • Do not fail to backup your Outlook PST file on other storage devices
  • Avoid mishandling of Outlook and its PST file to shun PST corruption