Looking at the RuleID we would assume that the error comes from your custom rule
@StefanSchnell has started a discussion on rule naming conventions
we would suggest to follow as close as possible the conventions (makes also easier to identify/group the rues). In my case we handled this as we used the Company Token within the RuleID on the last part:
The error looks that somewhere a Regex pattern? is null. Maybe remote debugging of the rule will help you to sort it out:
- attach to remote process - UiPath.Studio.Analyzer
- set a breakpoint somewhere you would assume the issue
- start debugging
- analyze it within the different inspection panels