When you reinstall and deploy a solution in Moss, an existing solution is prompted.

A solution has been deployed before. If you reinstall it, there is no problem, but the following error will be reported during deployment:

"You have installed the f7a21215-0997-47ff-a9fa-3c7bd3719944-ID feature in this server farm. Please use force properties to explicitly reinstall this feature. "

The Force attribute here is actually-Force. When using the stsadm tool, it will be OK after deploysolution.

At the beginning, I thought that the mandatory attribute is mandatory installation. Therefore, after addsolution, the result is that the parameter is invalid.

I learned later that it should be "forced deployment" instead of "Force re-installation". Haha !!