Bruce Johnson provided a graphic image of the risks in waiting too long to convert your app(s) to the current version of Clarion. You probably don't want to be the first person in the river, but you also don't want to be the last Clarion wildebeest on the bank after the herd has gone through.
The longer you wait to convert, the harder it gets. Bruce indicated the move from Clarion 5.5 to Clarion 6 was one of the most difficult. Going from 6 to 8 is much easier. Going from Legacy to ABC is also quite difficult.
You're also running the risk that one day your program won't work any more because the operating system is no longer there (e.g. 16 bit apps).
Six steps
Bruce broke the conversion process into six steps.
Step 1: Update your third party products to their "modern" C6 versions.
Step 2: identify third party requirements and update those you can. Identify the ones that are no longer available/supported and find alternatives.
Step 3: Prepare the C8 environment. Install waht's available and manually install stuff that's not available as a C8-ready product.
Step 4: Open the app and try to generate/compile
Step 5: Tidy up the solution
Step 6: Compile and run
To which I'd add that if you use any third party DLLs be scrupulous about checking for any lingering dependencies on the C6 runtime.
Bruce went over some of the common template issues including spurious #SEQ attributes and missing END statements, as well as some of the window and report definition errors you may encounter.
Any time you get an unknown template error on converting an app, do not save the app. Get the necessary template and try again.
A must-view for anyone with apps to upgrade. Look for the recording at http://clarionlive.com/