Hi lewiss945,
welcome to the Rebex forum and thanks for bringing this to our attention.
Support for the .Net Core platform on Linux and MacOS is experimental. Experimental support is mentioned on our product page(please have a look at https://www.rebex.net/total-pack/default.aspx.)
I have probably identified source of the exception. If you are interested, drop me an email at support@rebex.net and I will be glad to prepare hotfix for you.
Thanks!
