Hi there Scrubanne,
Welcome to the Apple Support Communities! It sounds like you are receiving an error when trying to import pictures from your iPhone to the Photos app on your Mac. I definitely want to ensure that you're able to move over pictures to your Mac, and I'll be more than happy to provide you with some resources.
To begin, let's have you create a backup of your computer and your phone. I've included two articles that detail this process:
Use Time Machine to back up or restore your Mac
How to back up your iPhone, iPad, and iPod touch
Once we know that both devices have been backed up, we'll want to check for software updates. Based on your message, it sounds like your Mac is running 10.11.5. We did recently release 10.11.6, as well as an update for the iPhone. It's entirely possible that by updating both devices, that will resolve the issue you're experiencing. I've included instructions on how to update both your iPhone and your Mac:
Update the software on your Mac
Update the iOS software on your iPhone, iPad, or iPod touch
If you're still running into issues after completing the updates, I'd suggest trying to import the pictures while in safe mode. This helps us rule out any user login items or cached items that may be causing issues. Here are the steps for booting your Mac into safe mode and what to do if the issue doesn't occur:
Try safe mode if your Mac doesn't finish starting up
In the event that you still can't import the pictures into the Photos app, we'll want to have you create a test user account. This helps us isolate if the issue is user-specific or system wide. Check out the following resource for details:
How to test an issue in another user account on your Mac
You'll want to pay special attention to this section:
If performing the same steps in a test user account doesn't result in the same unexpected behavior, you most likely don't need to reinstall any apps or OS X.
- If an issue only happens in one app, check the app's documentation or support website for instructions on troubleshooting specific preference or setting files.
- If you need help with a specific alert message or issue, search the Apple Support website for the text of the alert message you're seeing.
If the same unexpected behavior happens in more than one user account on your Mac, try checking for software or hardware issues.
All the best!
