the following targets could not be opened and will be removed from the workspace

hello everyone , i try to open my workspace in a machine windows 64bits , but i have the following message : the following targets could not be opened and will be removed from the workspace for information:my application was developped in a 32 bits machine and the version of PB is 12.0 Classic . question : what should i do to solve this issue ? thanks in advance for your help .

Marouane