From drawing? save as pdf.
There is one more trick is to use keyword phrase like this illustrator repair for search machine or apply manual guide below
Check for a damaged pattern, gradient, or custom color
To determine if the problem is caused by a damaged pattern, gradient, or custom color:
1. Choose Edit > Select All and change the fill and stroke to process black.
2. Perform task 4 again to determine whether the problem occurs in a new file that does not contain the patterns, gradients, or spot colors. If the problem does not recur, re-create the pattern, gradient, or spot color in the original file.