invalid file name error when using Grd2MIke

I run into this error every once in a while, and I am having a hard time finding a reason.

When using the Grd2Mike tool when i select my .asc file I sometime get an error of "invalid file name. I have no spaces in any of my file names and am just wondering if I am missing something silly.

Best,

Jake

I think it is related to read access issue if the .asc file is opened in ArcGIS simultaneously.
If you close ArcGIS (or any other s/w accessing the file) you should be able to proceed to the next dialog of the tool. I just reproduced and it is working as expected.

I also get it sometimes with Dropbox synching.

I cannot directly give you the reason, but it seems to me that the tool grd2mike is having problems with longer file paths. If I copy the asc file to C:temp/file.asc, I don't get the error anymore.