Web Filter False Syntax Error

Trying to update my item filters for my handful of subscribers, but they get rejected with "Please resolve the syntax errors. Letters, numbers and punctuation only.". I thought this pointed at the line of the error?

However, that's secondary because the filters all load in-game just fine, so something wonky is going on with the web parsing.

Thanks!

Edit: I went through and made the changes for the league again from the previous version, and it uploaded fine. I'm assuming there's an extra space somewhere that gets caught by the web parser but isn't relevant when the actual game processes it.

Edit 2: Instead of resurrecting I'll just leave this here for someone to find. The issue happened again but this time I scoured the filter for the errors more finely and found that the breaking characters can be in commented out sections (such as interface elements for Filterblast).