Getting error HTTPMaxCollectionKeys threshold limit reached when trying to configure a webpart.
Title
HTTPMaxCollectionKeys threshold limit reachedDescription
Cause
Reason of the issue:
When you edit Viewed Lists of the qListView by using ezEdit, it will show you all the SPLists of the site. Then you select one of the SPLists and click OK to save the configuration. The webform will post your request back to the server. Image that there are about 500 SPLists on this webform, each SPLists have 2 parameters. The web form itself also contains the other parameters. So there are more than 1000 parameters that need to be submitted to the web server. But IIS just allows 1000 parameters to be submitted in one webform by default. So you will see the error message threw by IIS to tell you that the MaxHttpCollectionKeys Exceeded.
Resolution
Workaround:
There are two options, please choose one base on your situation.
Option 1: Increase the value of MaxHttpCollectionKeys.
1) Open the web.config of your IIS on the web server.
2) Find <AppSettings>…</AppSettings> section.
3) Add this section to change the value of MaxHttpCollectionKeys, for example increase the value to 2000:
<add key="aspnet:MaxHttpCollectionKeys" value="2000" />
4) Save web.config.
See ScreenShot01.png (web.config example)
Option 2: Directly use xml to define Viewed Lists of qListView.
1) Open ezEdit of qListView. In Display tab, do not click Edit button of Viewed Lists, but directly input xml to define which SPList you want to show in qListView.
The format is:
<Lists>
<List SiteUrl="<site URL> " ListName="SPList 1" />
<List SiteUrl="<site URL>" ListName="SPList 2" />
…
<List SiteUrl="<site URL>" ListName="SPList n" />
</Lists>
For example, use qListView to show two SPLists MyLibrary100 and MyLibrary102, the site url is “http://dev_server/test/”. See ScreenShot02.png (list example).
Defect ID
Reason of the issue:
When you edit Viewed Lists of the qListView by using ezEdit, it will show you all the SPLists of the site. Then you select one of the SPLists and click OK to save the configuration. The webform will post your request back to the server. Image that there are about 500 SPLists on this webform, each SPLists have 2 parameters. The web form itself also contains the other parameters. So there are more than 1000 parameters that need to be submitted to the web server. But IIS just allows 1000 parameters to be submitted in one webform by default. So you will see the error message threw by IIS to tell you that the MaxHttpCollectionKeys Exceeded.