"Custom search" extra "Unknown error"

I bought and installed the custom search extra to see where a css class is used (wanted to change it a bit but first check if it would break things)

I searched for it in the all the content (resources, chunks, templates etc) and gave me a result.

Now, when I search for that same term I get “Unknown Error – possible invalid search string”

On further examination, when searching for strings that I know are there, it sometimes gives me results and other times gives me that error…

Running MODX Revolution 2.8.3-pl

@bobray , I was planning to email you via your website but saw you prefer support questions to be directed at the forum… Since this is a paid extra you offer from your website, let me know if you prefer the conversation here or private

Sorry about the trouble. Please use the contact form at Bob’s Guides. Give me the exact search string and options, and the details about the string you’re searching for (that is, what MODX object is it embedded in and what’s the surrounding text of the target string).