SVG as data URI triggers XML parsing error in Firefox

It is not valid for data URIs to contain # characters like yours has, you must escape them as %23

The unescaped # character is reserved to indicate the start of a fragment identifier. Firefox is quite right to indicate a parsing error.

you can use the online tool https://www.zhangxinxu.com/sp/svgo/

it support let special characters encoded, such as:

"" => %22
# => %23
% => %25 ...