website down for Invalid argument supplied for foreach() in

[dante75]

hi there,
today I'm getting this error than makes my site disappear. NOthing was done to the website, it simply appeared out of nowhere:

[16-Oct-2010 12:17:51] PHP Warning:  Invalid argument supplied for foreach() in /public_html/classes/Category.php on line 320
[16-Oct-2010 12:17:51] PHP Warning:  Invalid argument supplied for foreach() in /public_html/classes/Tools.php on line 855
[16-Oct-2010 12:17:51] PHP Warning:  uasort() [function.uasort]: The argument should be an array in /public_html/classes/Tools.php on line 858
[16-Oct-2010 12:17:51] PHP Warning:  Invalid argument supplied for foreach() in /public_html/classes/Tools.php on line 861

my site was down (front and back) for 4 hours, then it was back live by itself for around 30 minutes before going blank again.
I'm really worried because I have not idea on what caused , what to do to fix it and what to do to prevent it happening again.


if anyone able to help me with this, it'd be very appreciated.
thanks

[keutche]

Hi,

did you add any new module lately ?

Keutche

[dante75]

hi ,

thanks for your reply.

no I haven't installed any module lately and not work had been done as well. The error simply appeared out of no where. In the mean time, after hours the error disappeared and the site was back live.

I had a look to the forum and this issue seems to disappear after few hours by itself. I'm not exactly sure about what happened and it worries me a bit that the same error could came back at any stage and put me out of business.

I'd like to fix the issue so that won't present itself again.

Thanks