The FIP-FS "Microsoft" Scan Engine failed to load., Error Code: 0x80004005. Error Description: Can't convert "2201010003" to long. / Event ID 5300

You may face the problem unable to send email internally and receive any email on 01 Jan 2022 if you have installed and enabled Exchange Malware Agent. You may see the event id 5300 indicate below.

The FIP-FS "Microsoft" Scan Engine failed to load. PID: xxxx, Error Code: 0x80004005. Error Description: Can't convert "2201010003" to long. / Event ID 5300

To verify and you may run below. A Malware agent will list and indicate status if you have installed.

Get-TransportAgent

There are 2 workaround temporary. I have tested both and it's working.

Workaround #1 (Disable Antimalware)

1. Disable the malware agent in the Exchange Management Shell:

$env:ExchangeInstallPath\Scripts\Disable-AntimalwareScanning.ps1

NOTE: Require to change to Exchange installation scripts folder.

2. Restart the Exchange Transport service to take effect.

Restart-Service MSExchangeTransport

Workaround #2 (By Passing Antimalware)

1. By passing the malware agent in the Exchange Management Shell:

Set-MalwareFilteringServer -Identity Mailbox01 -BypassFiltering $true

 NOTE: Change the identity to the hostname of Exchange.

2. Restart the Exchange Transport service to take effect.

Restart-Service MSExchangeTransport