Chrome depreciated one of the features that allowed these popups to work, here is a temporary workaround to get it working.
Download the Chrome Policy Plugin here
- Open the zip file you just downloaded and locate the .ADM file that best matches your system:
- Extract the .ADM file to any folder on your hard drive
- Go to Start > Run, and run gpedit.msc
- Right-click Local Computer Policy > Computer Configuration > Administrative Templates, and select Add/Remove Templates:
- Add the adm template that you saved to disk earlier:
- You should now see the template underneath a Google > Google Chrome section within Administrative Templates
- Depending on which operating system you have, it might be under a Classic Administrative Templates (ADM) folder:
- Click on Google Chrome in the left-hand pane and then double-click on the item called Enable deprecated web platform features in the list within the right-hand pane:
- NOTE: It helps to sort the table in the right-hand pane by the Setting column in order to find the Enable deprecated web platform features item more easily.
- In the new screen that appears, click the Enabled radio button:
- In the Options section of the same screen, click the Show… button
- On the new screen that appears, type ShowModalDialog_EffectiveUntil20150430 into the first cell of the table that’s displayed and hit ENTER: -IMPORTANT NOTE: Make sure there are no spaces either before or after the ShowModalDialog_EffectiveUntil20150430 Otherwise, Chrome will reject the setting (see the Troubleshooting section for more information).
- Click OK
- To verify that this policy has taken effect, navigate to the following URL in Chrome: chrome://policy
- If everything is set up correctly, you should see a screen like the following