So basically there's a problem when reading the .dis file (so far). What is the problem with the format? I actually looked at the .dis format in the MODFLOW guidelines for input files and there seems to be nothing wrong.
Mr. Sebastián Aedo
Subject: Re: Issue when reading MODFLOW files from WEAP Posted: 9/7/2021 Viewed: 1674 times
I've been through the same issue when using fixed format and fixed it by erasing the space between the real number (50.0000 in your case) and the format ( (10E12.4) in your case ). The same will happen with 1D or 2D arrays when you set IPRN = -1. I would suggest using free format to manually edit the packages.
It seems to be an issue on how WEAP read and rewrite the packages.
Sebastián Aedo Q.
Topic "Issue when reading MODFLOW files from WEAP"