'The page cannot be displayed' When Clicking on Member Selection Icon for a Dimension in Data Form

For one of our clients we faced this issue, When we were clicking on member selection Icon  for a data form for a dimension we were getting Page cannot be displayed error, this was happening to one data form and while selecting members for one dimension. We requested client to copy the members which are present in Member Selection Text box to a notepad then we found that is a huge list of members, here client randomly typed the members separated by comma. When we deleted all the members and then clicked on member selection icon it worked. 

Why this happens:

In this example IDescendants(Account) is converted into a part of URL so that It can be passed 

to the next page; variable which stores this is &SEL_RTP_MBRS, For testing the same I have 

passed Sales several times and checked the length of the Location URL, I found  As long as 

the length of the URL is less the 2084 it will work fine, the moment it will be 

more then or equal to 2084 you will get the blank page.

Now lets have a look at our Fiddler trace.

This is a real big for our POST 

http://localhost:8300/HyperionPlanning/servlet/HspMemberSelect  to handle, so this errors out 

with blank page.

Solution

To get rid of blank page, delete the member in the member selection text box manually, now click on select member Icon and if possible select your members using functions like Idescendants, descendants, Siblings, Children etc function to keep the length short.
Or if you 'have' to use many members in the select box then you need to manually enter the member names, edit the member selection in the member selection text box it self.
Note: You will face this error only while selecting members, data form will work fine without issues. 

Cheers...!!!