Unable to open MailEnable Administrator console on a Plesk server: Unable to load DLL 'MEAISO.DLL': The specified module could not be found

Symptoms

Unable to open MailEnable Administrator console at Windows > MailEnable. The following error is shown:


CONFIG_TEXT: Unable to load DLL 'MEAIPO.DLL': The specified module could not be found. (Exception from HRESULT: 0x8007007E)
Unable to load DLL 'MEAISO.DLL': The specified module could not be found. (Exception from HRESULT: 0x8007007E)

Cause

The MailEnable related environment variable is missing in the PATH system variable.

Resolution

It is required to add these variables to the PATH system variable.:

1. Log in to the server via RDP.
2. Open My Computer > Right-click This PC > Properties;
3. Click Advanced System Settings (righ-hand side), and then Environment Variables:
4. Select PATH in System Variables > Edit:
   
   
5. Append the path to MailEnable binary directories there. For example, on Plesk Onyx that was not upgraded from previous versions, the following path should be added:

   PLESK_INFO: C:\Program Files (x86)\Plesk\Mail Servers\Mail Enable\Bin64;C:\Program Files (x86)\Plesk\Mail Servers\Mail Enable\Bin

6. Restart all related MailEnable services:
   

Note: The path in step 4 may vary based on the upgrade history or installation specifications. Adjust it accordingly.