When attempting to view AMOS text output, the warning message, 'This output file is in an obsolete format. It can be viewed. However, some features of the output viewer will be unavailable' present. The warning window title ('blue bar') contains 'PAAppViewer' or PAAppViewer3' and the only response option is 'OK'.
There may be multiple causes for this behavior, but at least one cause was determined to be an issue with file associations.
Diagnosing the problem
Check the extension of the output file. The extension should be 'AmosOutput'. If it is not, then the file is not being created with the correct extension. If the file does have correct 'AmosOutput' extension, the problem may be due to a failure of the operating system to have the correct file associations for the 'AmosOutput' file type.
Resolving the problem
Test the content of the file by changing the file extension to 'htm' or 'html' and opening in a web browser. If the file displays normally, then the problem is not with Amos, but most possibly with the operating system file associations for 'AmosOutput' files. Change the default executable associated with the 'AmosOutput' file extension to 'AppViewerCLI.exe'.