Issue: 

Trying to export galleries and seeing this error in the admin header (not log)

Warning: /var/export/gallery/Album_20201109131959.csv): failed to open stream: No such file or directory in /home/justinb/public_html/vendor/magento/framework/File/Csv.php on line 154


Solution: 


The root of the issue is that the folder /export/gallery does not have permission to create files.

To solve the issue, please change two files:

app/code/Bss/Gallery/Controller/Adminhtml/Export/ExportCategory.php

app/code/Bss/Gallery/Controller/Adminhtml/Export/ExportItem.php 

Please replace two files on the site and flush the cache.


If you need any help, please feel free to contact us.