It has been a great extension, but lately, YouTube ads have been saying "An error occurred. Please try again later" instead of just being skipped.

good and effective

Last update started to request access to IP Address:

See release notes.

Changes:

uBO requires a new permission, dns, which is required to solve issue 780. This may triggers a new permission warning from Firefox when uBO updates to the latest dev build, specifically "Access IP address and hostname information", even though this was already possible for uBO to access that information.

From now on uBO will CNAME-uncloak network requests. CNAME-uncloaked network requests will appear as blue entries in the popup panel and the logger. The uncloaked entries in the popup panel will also show the related aliases (in smaller characters underneath the canonical names).

Network requests which were blocked, redirected, or excepted by a filter/rule are not uncloaked. Canonical hostnames which are first party to the associated alias hostname are not fed back into uBO's filtering engine.

Warning: CNAME-aliased hostnames exist most likely for content delivery purpose, i.e. legitimate.

Please move the reload button to the right

"Important: the statement "IP address" refers to the IP address of the servers to which your browser connects, NOT your specific IP address. uBO has no access to (and no need to know) your specific IP address."
https://github.com/gorhill/uBlock/wiki/Permissions#access-ip-address-and-hostname-information

I'm very satisfied with this extension. Default options right after installation are generally fine. If you want better results, It takes some time to learn about all the available options but the more you learn the more you'll benefit from this fast, light and very customizable extension.