Hello
I'm Apex new comer, but with experience with Oracle. The thing is that creating a new App I found that when I try to make any style modification with the Theme Roller, it simply can't save those changes. Looking more in detail I noticed that the saving process is throwing an error

My installation of Apex is based on a Centos 7.8 OS, Oracle 18C EX, Apex 20.1 and using ORDS 19.4 as webserver.
Looking for an solution, I decided to test the Theme Roller on another Apex server which is a Centos 7.8 OS, Oracle 11g EX, Apex 20.1 and using the "Apex web server", and using the same web browser I could successfully save the theme style without any issue.
I also tried to "move" the theme style I've created with the working Apex deploy with the export and import option, but so far without success, I assume because I'm using on both Apex the 42. Universal Template, and so It can't be modified. I tried to generate a new template and make some modifications over it, but the CSS is not included on the export.
Any help would be highly appreciated.