After applying form security, I can no longer open the form. It gives following error:"This is the Pro version. Opening this form is not allowed."

The problem occurs to the form having subform(s).  The problem is that ChemFinder is inserting security information to subform.  You can remove security information manually by opening *cfx file in text editor.

To fix the form:

1.  Open *.cfx with text editor (i.e., Notepad)

2. Search for "Security"

Note: There should be multiple Security entries.  First entry should be there.  The rest of security should be emptied

3. Leave the first security only, delete the contents of security for the rest.  For example:

Original:

<security username="aaa" password="MFIGCSsGAQQBgjdYA6BFMEMGCisGAQQBgjdYAwGgNTAzAgMCAAACAmYCAgIAgAQI&#013;&#010;5S4srZxArdkEEDIhGPijyn5LPzHvLIILh8EECOf1lVpqNH<O></O>

Xa&#013;&#010;"></security>

Change:

<security></security>

4. Save the file

At this point, you should be able to open the form.