Pages of errors in error log since 7.05 upgrade

[foodsleuth]

Hi,
I just checked our error log and we have about 60 of these errors in our error log since our upgrade to 7.05 yesterday. Can someone say what this error means?

Exception of type 'System.Web.HttpUnhandledException' was thrown.; Object reference not set to an instance of an object

[mazhar]

Do you have any information about exact location causing this problem or process that can trigger this issue?

[foodsleuth]

99% are all being called from CategoryGrid4.aspx with only a few errors from Defaul.aspx and Basket.aspx

Sample:
An error has occured at http://store.gourmetsleuth.com/Category ... CategoryId(happens with/any all ids)
An error has occured at http://store.gourmetsleuth.com/Default.aspx

Given the time and frequency of the errors it looks like they are occuring with bot activity, but not sure.

[foodsleuth]

Can we get some help from Able on this? Our error log was virtually "error free" before the 7.05 upgrade so clearly it is related somehow. Any suggestions?

[mazhar]

Do you have any custom thing on this page? Any code change to CategoryGridPage4? I tried to replicate the issue on my local install of 7.0.5 but it worked flawlessly. It makes me feel that may be there is something custom in there.