Space import error incorrect

When trying to import a space, I get the error
"

• Your request could not be processed because a required security token was not present in the request. You may need to re-submit the form or reload the page.

"

When I debugged confluence (hitting the error in com.atlassian.xwork.interceptors.XsrfTokenInterceptor#intercept:90) that's actually not correct. The true error (in ServletActionContext.getRequest().errors), that's being masked by this no token error, is a "java.io.IOException: Content Length Error (2147487250 > 2147483647)"

I think a few customers are experiencing this problem too

https://community.atlassian.com/t5/Confluence-questions/import-space-and-site-fails-a-required-security-token-was-not/qaq-p/173733

https://community.atlassian.com/t5/Confluence-questions/Required-Security-Token-was-not-present-in-request/qaq-p/24631

https://community.atlassian.com/t5/Questions/Importing-and-Exporting-Spaces-from-Confluence-getting-a/qaq-p/422920

https://community.atlassian.com/t5/Confluence-questions/Required-security-token-when-restoring-from-backup/qaq-p/137169

Done When

• Showing users the correct error