Well that's not much information to go on, I can't help if I don't know what your issue is.

Installation / Upgrading is no different than any other vBulletin install / upgrade.

Got it to work - have only problem with this plugin - https://www.vbulletin.org/forum/show...hlight=chatbox
Ibproarcade works fine what is most important for me!

Thanks for your work!

Will explain what caused problem!
When we installed vb 3.8.11 - we got message that we must delete install directory for access to admin cp
when uploaded your files - install directory missing some vbulletin files - i copied vbulletin files and could run upgrade.php - otherwise was just blank screen!

regards

glad you figured it out, yes that's basic vBulletin procedure when upgrading / installing you must always have the install folder. Instead of deleting the folder from your server for future need, it is better practice to rename it something random. like .34hp98hregf798dhpg9

Does the Vbseo plugin work with it?

vBSEO hasn't been updated in YEARS and the last release of it had vulnerabilities. I wouldn't count on it.