There is a known issue in SOLIDWORKS 2017, where enabling the Toolbox Add-ins causes SOLIDWORKS to hang. This issue is reported in the Software Performance Report (SPR) 1002311 and will be implemented in SOLIDWORKS 2018 b1.
Enabling the Toolbox or Toolbox Utilities Add-in from either the Command Manager or Tools>Add-ins, will cause SOLIDWORKS to hang.
The solution to this issue is to close the SOLIDWORKS application and delete the "tb_default.sldedb" file from C:\Users\<user>\AppData\Roaming\SOLIDWORKS\SOLIDWORKS 2017\Toolbox\data. When you open SOLIDWORKS and enable the Toolbox Add-ins a new "tb_default.sldedb" file will be created.