Sometimes the downloaded package gets corrupted and you see this error while uploading the package of installing the plugins. However this can be simply avoided by using the FTP method.
Here are steps to fix this issue:
1. Download the Package from Themeforest.
2. Unzip the Package.
3. Unzip the WPLMS.zip theme file
4. Inside the unzipped folder locate the plugins folder.
5. Copy all the .zip files in this folder to your desktop.
6. Now login via FTP to your server and locate the the WP Content -> Plugins directory.
7. Upload each of these zip files in the directory.
8. Unzip each of these files in the directory.
9. Now, login to WP Admin
10. Go to Plugins and you’ll see all the plugins in it.
11. Activate each of these plugins to get started.