BackupBuddy: Advanced Debugging
FTP Transfers Fail
- Login credentials are wrong. Test them to be sure. This is surprisingly common. View the HTML source to obtain the hidden password.
- The path entered is incorrect or the directory has not been created. BackupBuddy requires the path to already exist.
- Some hosts block outgoing FTP connections, port 21 (standard FTP port), and/or do not have the FTP extension available for their PHP installation. This can easily be tested by entering settings for a known working FTP or by taking the FTP settings the user entered and trying them in an FTP client.
Scheduled Events Fail to Trigger
- The scheduled date is wrong and has not passed.
- Not enough visitors are visiting to trigger the schedule. Someone must visit any page on the WordPress site on or after the scheduled time for the event to occur. If no one visits during the time-frame then the event may be missed or occur at an unscheduled time.
- The backup is failing. Test manual backups.
Warning: mysql_query() [function.mysql-query]: Unable to save result set in /www/wp-content/plugins/backupbuddy/backupbuddy.php on line 1673
- This is usually caused by a corrupt database or corrupt table(s) within said database. Repairing the database/table(s) using a tool such as phpMyAdmin typically resolves this issue. 
Importing / Migrating with importbuddy.php
The source site is now redirecting to the destination site (or vice versa):
- This occurs if the new database settings were not entered during Step 4 of importbuddy.php. Because of this, both sites are now sharing the same database so one of them (usually source) is redirecting to the other (usually destination). importbuddy.php needs to be re-run inputting the source URL on Step 4 and using the source database settings. This will reconfigure the source database to use its proper URL. Next importbuddy.php needs to be run again inputting the destination URL on Step 4 with the NEW database settings for the new database. This way both sites will have their own database for their respective URLs.
ERROR #59233894: NOTE: Did you refresh after finishing the import? If so, [...] This error indicates that BackupBuddy was unable to detect the file 'backupbuddy_dat.php' in the current directory nor wp-content/uploads/temp_XXXXXX/backupbuddy_dat.php where XXXXXX are the random characters found in the ZIP file name.
500 Server Errors:
- .htaccess file is causing URLs to be redirected improperly or is malformed.
- PHP is not functioning or enabled for the site. Check with basic phpinfo().
- A 404 error is occurring but the server is not set up correctly to return a 404. Do sanity check with .htm file.
The backup zip file is not found:
- The zip file has been renamed to a non-BackupBuddy format.
- The zip file permissions are wrong. Ex: Not readable.
- The zip file is not in the same directory as importbuddy.php.
- The zip file has not finished uploading or was interrupted in transit. If BackupBuddy was used to send it try manually uploading.