Cannot post from desk top computer

[NChick]

Beginning a few weeks ago I can't post to the CMP forum using my Dell desk top computer (uses Firefox). When I try to preview or post a message, I'm returned to the composition page with all my entered text deleted and an error message that my message needs to be over two characters long to be accepted. Clicking on emogies has no result. I have tried cleaning my cache without positive effect. I am currently using a Samsung tablet running on Chrome to enter this post. Can anyone tell me what the problem is? I have no problem posting to other web sites that use the same forum software as CMP. TIA!