"Cannot access your files"

My site shows error 403
In the dashboard I cannot access my files. It shows this message:

Cannot access your files, it could be a temporary problem due to an update or technical failure. In this case, if the problem persists for more than two hours, notify it on the forum.

Can I recover my site, please?
How do I do it?

Thanks!

My site shows error 403
In the dashboard I cannot access my files. It shows this message:

Cannot access your files, it could be a temporary problem due to an update or technical failure. In this case, if the problem persists for more than two hours, notify it on the forum.

Can I recover my site, please?
How do I do it?

Thanks!

I see this when I try to enter as admin

Parse error: syntax error, unexpected '{', expecting T_STRING or T_VARIABLE or '$' in /membri/ikonomia/wp-content/plugins/leads/classes/class.batch-processing.php on line 80