Hello, first two things...
I moved your post to a more appropriate forum so it can be more useful to you and others in the future. :)
Second, your pasted error details contain a website address. It's not a big deal to any of us, but you may want to consider obscuring identifying details like that in your posts. For example, if a hacker reads it, they have more details about how to attack the website you've listed.
Now to your question...
It's not a good idea to use the HTML module for anything more advanced than general content updates. Even then, most people tend to use a structured content solution instead. The limitation is really due to what any online content editor can support. They still have issues with these sorts of things and maybe will for a long time.
In the meantime, I'd instead suggest using the IFrame module. It's built to support IFrames in a direct way and you shouldn't have to run into this.
If the IFrame module can't be used for some reason, then you might need to use a structured content solution instead as well. OpenContent and 2sxc seem to be the most popular options at the moment.