Computer crashed while editing cards

It already happened several times. While I was editing cards, the screen just froze up. Only the tracking pad was working. I could move the cursor, but the system does not respond at all. I had to hard reboot the computer. MBP 2015 16G/256G 10.12.6

Is that your version of MacOS? If so, updating the OS to a current version might help; for a developer it is very low priority to fix a bug for an outdated OS that few people still use.

I did a clean install upgrading to 12.14.6, still having the same problem.

We are very sorry about the inconvenience caused.May I ask the version of MN?

By the way, latest OS may help since the xcode GCC we’re using is provided by Apple and designed for latest OS. The compatibility problem may caused by GCC.

First, let me check your MN version and solve it together.
Second, how’s the OCR option, emphasis option etc. Which tools may caused a crash. A screenshot may help us locate the problem.

I am on MN3 trail version actually.

The data I am using was transferred from MN2. All the functions works fine except for editing cards.

What happened was that while I was scrolling up and down on the left section of the picture, the whole app just getting slower and slower. As I kept scrolling, the computer would finally stop responding. So I had to hard reboot the mac.