Iam currently investigating what is the cause of this, on KNIME side as well as on Excel. What I found out is that if you display all columns (currently a lot of them are hidden) it reads the files very fast. So you could try to unhide all columns which can be quiet time consuming and annoying. Another workaround for the time being is to use XLS files instead of XLSX or use the option “Reevaluate formulas” in the Advanced settings tab if possible (here the file is treated as a XLS File). For the latter approach you should be aware that the whole file needs to be loaded in memory which can cause some problems if the files are big.
Either way, we hope we can we can find a solution as soon as possible!
I think it has something to do with the format of the File(s) which we (KNIME) or the underlying used library does not like. I could not reproduce the issue by creating an own file which hides a lot of columns. Do you use some special formatting or something like that?
Best regards
Lars