For those of you that run into the same issue, it looks like it's an issue with how the MMC for MailEnable is created during setup. The MailEnable snap-in is 32 bit and the MMC must be setup using the /32 parameter.

Please reference https://www.mailenable.com/kb/content/article.asp?ID=ME020274

Thanks for the reply. I also just tried version 10.29 and got the same error. I did just e-mail that address and hope to hear back. If I read the error message right, it might not even be my post office name (I've tried several versions, including just "Home"), but nothing takes. I'm starting to thi...

Sorry for posting twice. I wasn't sure that my original message posted.

I found the instructions to remove the software, rebooted and reinstalled and it came up with the same error.

Does anyone have any suggestions?

I just installed 10.28 onto my Windows Server 2019 Essentials system and getting the same error. Illegal PO.png I've done as suggested above and keep getting the same results. The uninstaller isn't working, but I'm also trying to use previous builds. When I tested this on a test machine a few months...

I just downloaded and installed version 10.28 onto our Windows Server 2019 Essentials and I keep getting the same error. I've even tried to uninstall (but that fails.)

I've done as suggest above and removed files, started over and even confirmed that the .tab files are correct.