Ensure the hardware complies with the System Requirements:
SolidWorks:
https://www.solidworks.com/sw/support/SystemRequirements.html
MDTools:
https://VESTusa.com/Manifold-Design_MDTools-900-Series_System-Requirements.htm
Ensure that the latest Service Packs are installed.
SolidWorks:
Open SolidWorks > Help > Check for Updates.
MDTools:
https://VESTusa.com/Manifold-Design_MDTools-900-Series_Service-Packs.htm