wpForo don’t accept wordpress credentials to log in

Hi oscar72,
If you don’t have important information in forum, could you please Uninstall (not Deactivate), then install it again. This will remove all forum data and do fresh installation. I think this issue is user specific issue. This is not a general issue and nor wpForo bug.
Also I’d recommend deactivate all plugins and test it. This may be a plugin conflict.

Before uninstalling the wpForo plugin I would like to know if the problem may depend on what is explained in this post on the wpForo support site: https://wpforo.com/community/how-to-and-troubleshooting-2/unable-to- login-to-forum / post-7700 #
Because if so, I do not know what to do. I have a wordpress.com business plan, so I can not remove the jetpack plugin

I do not know why, but I can paste the correct post url of the article. I’ve cut out it and posted it on this page of my site
https://libricitygroup.com/wpforo/

Sorry but i am a beginner

All maybe, before uninstalling please disable all plugins and test it again.
The post you mentioned is also related to other plugin, this is the wordpress.com general login plugin and it may affect the forum login process as well.
I think your issue is a plugin conflict issue, rather than installation issue.

I disabled the plugins I was allowed to disable. As I said, having a wordpress.com plan and not www.remarpro.com, there are default plugins that I can not disable.

Now it came back to a problem that was presented yesterday too. When I login to forum, the browser open a blank page with the text:

Error 500
The server encountered a syntax error, and could not complete your request.

That’s strange, it seems you also have installation issue. wpForo doesn’t have syntax errors. It seems something was incorrectly installed. Please do:
1. Uninstall
2. Delete plugin
3. Search ad install it again.

I’ve uninstall the plugin, delete it and installed it again. But it’s not resolve the problem.
When I reinstall the plugin I find the forum exactly as it was before, already setted and with all the categories created and the contents inserted, as if it had not been deleted from memory.
I did not just disable the plugin, but I followed the recommended steps: I deleted it and then downloaded it again.

Is this a user specific? If so just delete the user you use and create a new one.
Where can we test it?

Sorry. I was wrong in following the directions given. Now I did as described: uninstall, delete plugin and re-installed it again.

Now the forum is in the default state and before touching everything I tried to log on. But the problem remains. If I join to the site with my wordpress credentials (administrator user), from the classic access panel, I’m already logged in to the forum, but if I log out and try to re-enter from the wpForo login, it tells me the password is wrong or it reopens the white screen with “Error 500
The server encountered a syntax error and could not complete your request. “

What do you main with: Where can we test it?
Can you remotely test it?