Ok. I found a solution that worked for me so maybe it will work for you too.
1. My host did something to speed up the processing. When i tried it after that adjustment I still received the error message.
2. I found a post from 2 years ago where a guy tried limiting the number of products added at one time, so I tried that and it worked. For example. I am adding t-shirts to my store. One design had the option for 10 different colors and 6 different sizes.(60 items at once) I dropped it down to 2 colors and 3 sizes (6 items at once) and it successfully added to the store. Once added, I edited the variants of the product to adjust the colors and sizes back to how I wanted them.
I don’t know if it was a combination of doing both 1 & 2 or just doing #2. I would suggest doing number 2 and seeing if it works for you.
Good luck!
