Adobe Premiere - how do I find a clip using a removed plugin?
In premiere Pro CC 2015, you can use the find on timeline command by pressing (Cntrol+F) for windows and for mac (Command+F) the dialog box that opens up will help you find the clip.

Chose from the dropdown "effects" the chose "contains" and type "name_of_plugin".

replace the name_of_plugin with the name of the plugin you used and gave you errors. Mostly it should find it. 



I tested this with an inbuilt plugin of premiere called "Calculations" within channel in video effects and it does find the clip. The only difference is that I did not delete the plugin itself while testing as its in built. You should give this method a try and hope that the metadata needed for the same will be there.

P.S.: you could also try starts with instead of contains in the second drop down for better results.

Good luck.