Comment 2 for bug 1508777

I can also reproduce the problem. I did the following:
1. Create some .png image and copy it multiple times. I have created 80 images.
2. Make Nautilus file manager and Pinta both visible like half of the screen.
3. Select all of the .png images and drag them to Pinta.
4. Pinta crashes with error message from bug report above.

I have also tested on Pinta 1.7-development from PPA and crash does not appear any more. It looks like this problem was already fixed in development.

You can do one of two ways to get this updates:
1. Install Pinta from pinta-daily PPA: https://pinta-project.com/pintaproject/pinta/howto/installing-pinta

Note: Above means it get get ugly if some development commit makes some regression bugs.
or

2. Download development version zip file and extract. You can do this without effecting existing Pinta or any other program on your system. Do the following:
a) From https://pinta-project.com/pintaproject/pinta/builds download latest working zip file (currently this is 1.7.0.232).
b) Extract zip archive.
c) In terminal execute command:
cd pinta
mono Pinta.exe
d) Check the Help | About menu if there is "1.7.xxx" displayed.

As stated above this is not going to effect existing official Pinta 1.6 version on your system or having no negative effect on your existing system.

If you don't like this new 1.7-development version you can just delete "pinta" directory.

Can you please test if this problem is solved in your environment in 1.7-development version.