When trying to enable production mode, it crashed with this error:
Interceptors generation… 4/7 [================>———--] 57% 23 secs 384.0 MiBPHP Fatal error: Declaration of Ubertheme\Ubdatamigration\Model\Indexer\Product\Category\Action\Full\Interceptor::execute(): Ubertheme\Ubdatamigration\Model\Indexer\Product\Category\Action\Full must be compatible with Magento\Catalog\Model\Indexer\Category\Product\Action\Full::execute(): Magento\Catalog\Model\Indexer\Category\Product\Action\Full in /home/germancarparts/public_html/generated/code/Ubertheme/Ubdatamigration/Model/Indexer/Product/Category/Action/Full/Interceptor.php on line 7  
Can you please help?
We’ve just replied to you via email regarding your subscription. Kindly check and follow up further with us there.
We see you’ve just sent us an additional question regarding updating your instance.
For now, please try with these steps first:
In your terminal, go to your Magento 2 root folder, and run these commands:
rm -rf app/code/Ubertheme/Ubdatamigration/Model/
rm -f app/code/Ubertheme/Ubdatamigration/etc/di.xml
If the issue still persists, then let us know here, we will check further.