I was having the same problem with several users not being able to open
custom forms and neither clearing the cache nor getting rid of it seemed to
consistently fix the problem. What did eventually work was to save the
custom form instead of trying to open it. Then go into Tools and select
FormsChoose Form. In the "Look in" drop down box select "User Templates in
File System" and then click on Browse. Find the folder you saved the saved
the custom form in and click OK. That form should be listed. Click on it
and open it and it should open the correct way. If you then go back to
ToolsFormsPublish Form As and Publish it to your personal forms library,
then all custom forms seem to open normally. It's worked for us anyway.

"Kelly" wrote:

I'm having a similar problem. I've created some custom forms, saved them to
my personal forms library, but when I try to access them I get the error
message that the form I'm trying to access cannot be displayed. I tried
going through the steps you've outlined below to no avail. What is the next
step? (Background: I was able to access them up until a couple weeks ago
when my email account had to be recreated. I haven't been able to display
any custom forms, just the standard ones. I can create new forms - but once
created and published I can't bring them up again.)