Hi, I've worked with 300K+ row Excel files in Prep so the data size isn't a problem. I've never seen that error before...have you tried following its suggestions and opening the file in Excel and doing a save as, then connecting to the new file in Prep?
Thanks for the response! Yes, I've tried that a couple times and I get the same result.
Are you able to share the data here, or a representative sample (that still generates the same error)? Also, what version of Prep & what OS are you using?
Did you try loading the file in Excel, saving it, and loading that in Tableau? That usually helps.
If you have Tableau Desktop, you might try the file there to see what happens too.
Either way, we'd love to see the file if you are able to share it.