SMD task may not be loaded after uninstalling 5.6.1 Hotfix because of upgrading OpenSSL. This issue mostly occurs in Domino 9.0 and 9.0.1.
The affected hotfixes are as follows:

• 5.6.1 EN Patch 5 Hot Fix B5017 or later (32/64 bit)
• 5.6.1 JP Patch 3 Hot Fix B5019 or later (32/64 bit)

For screen captures of errors when loading SMD tasks, kindly see the following:
The ordinal 3905 could not be located in the dynamic link library C:\Program Files\Trend Micro\ScanMail for Domino\program\V5.6.1.4920\SSLEAY32.dll

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The program can’t start because libssl-1_1-x64.dll is missing from your computer. Try reinstalling the program to fix this problem.

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The following is the SMD load debug log:
.\loader.cpp(120) 2023/01/06 11:04:09 "PreLoadLibary libcrypto-1_1-x64.dll failed, return 259, File does not exist."
.\loader.cpp(120) 2023/01/06 11:04:09 "PreLoadLibary libssl-1_1-x64.dll failed, return 259, File does not exist."
.\loader.cpp(120) 2023/01/06 11:07:40 "PreLoadLibary libcurl.dll failed, return 8630, File does not exist."
.\loader.cpp(120) 2023/01/06 11:07:42 "11 SMDLoadLibrary try to load C:\Program Files\Trend Micro\ScanMail for Domino\program\V5.6.1.4920\nsmdreal.dll failed, return 8630, P·"