Looked into this, and it's a bug in the internal code of the latest version of the XenForo software. Other users are running into the same problem on this version.
It appears the bug happens with any copy and pasted table that contains number columns and right alignment.
Hi, users were able to copy and paste from Google Sheets, and the formatting remained... once they submit the post, the formatting is not retained - this includes when they reply to a post with a table.
xenforo.com
When I paste a table copied from another site, the table gives this error. Is there any possibility to fix this? Print Preview
xenforo.com
This bug was introduced with version 2.3 of their forum software 9 months ago, and to date they have not bothered to fix it in all this time.
We're not going to wait for them though. I'm going to go into the code for the table parser and fix it myself, and then email their team with the fix so they can include it for everyone in the next software update.
