Don't know, and based on the info given, it's anyone's guess.
The more information you supply about your situation, the better equipped other community members will be to answer. Please supply the following Information where applicable:
• Adobe product and version number
• Operating system and version number
• Browser and version number (where applicable)
• The full text of any error message(s)
• What you were doing when the problem occurred
• Screenshots of the problem (if possible)
• Computer hardware, such as CPU; GPU; amount of RAM; etc.