When it hangs it says something like: Importing Discussions (x-y) then all of a sudden it just prints “-” every 5 seconds or so and nothing is being imported,
Unfortunately this reply comes far too late to help the OP, but hopefully, this will help someone else down the road.
First, before you begin your transfer of vBulletin, add the following lines to the top of your wp-config.php just below <?php
define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );
This will create a debug log of any errors you encounter, you can access the log by visiting
https://YOURDOMAINHERE.com/wp-content/debug.log
keep in mind that if your wp install is within another folder, you’ll have to alter the path in the url to access the log.
Next, once you’ve encountered an error, check your debug log, if the error isn’t listed, you can go to your MySQL tables.
Hit STOP on the Importer. (Don’t navigate from the page, just hit the stop button).
Go to the wp_options table (might be slightly different prefix depending on your own database settings) and do a search for %converter%
You will find 3 rows within the wp_options table
a. _bbp_converter_query
b. _bbp_converter_start
c. _bbp_converter_step
The Step will show you which step # your install is hung up on. The Converter query will tell you precisely which line and the start is what tells the bbp_converter where you last left off.
View the steps in your wp-content>plugins>bbpress>includes>admin>converter.php file
Step 1 (about line 339)
Step 2 about line 360, etc
Most often the issue is due to character collation.
