Hello,
Sorry for the delay in reply.
The error you’ve mentioned does not give the exact information that what cause the issue. However, there are multiple reasons for that. One thing I suggest you to check if your site has enabled DOMDocument extension or not. If not, then please contact your hosting provider to enable the DOMDocument (php-xml) extension on your site and then check again.
If this not helps, then please enable debug mode on your website and let us know what is the actual error so that we can assist you. To enable debug mode kindly follow the steps given in the following link.
Debugging in WordPress
Thanks,
if you have problems with commercial themes, not ones from ww.wp.xz.cn, you should contact author of the theme and they should be able to help you. You have https://helpcenter.qodeinteractive.com/hc/en-us for Bridge technical issues, and I am pretty sure they can help you.