Explanation
The error message indicates that the object with UUID ending in 18028821 has a dependency on another object with UUID ending in 7t00000i4e7a, which is missing from the target environment. Therefore, the first action to investigate the issue is to check whether the object with UUID ending in 7t00000i4e7a is included in this package or not. If not, then it should be added to the package or imported separately before importing the current package. Verified References: Appian Certified Lead Developer study guide, page 17, section
"Importing and Exporting Applications".