Not sure if related but last week I was doing some maintenance on an older program (not sure if 1.4 or 2.0).
Uploaded the program just fine with v2.1, but after making a change, it wouldn't let me download without flashing the PLC, which I couldn't shut the process down to do (plus leery of flashing working PLCs in critical applications anyway). Uploaded with 2.0 and it was able to do a runtime edit.
Are later versions not compatible with editing programs using earlier tech versions without upgrading the PLC? I thought I read here that you could do that, so long as you stayed within the feature set of the older version.
If you cannot do a PROGRAM mode edit, then you need to stick with the Do-more Designer version that matches your PLC.
It IS compatible as long as you do not use any 2.1 features, but it will tweak the System Configuration regardless, requiring a PROGRAM mode download (hence, no runtime edit). Note that once you download a project using Designer 2.1 to a 1.4 PLC, you CANNOT open it with Designer 1.4. But you CAN open it with 2.1 (and 2.2 and 2.3 and 3.0 and ...).
I have a 1.0 Do-more on my wall from 2012 and write a simple 2.1 project to it and it works with the original 1.0 firmware! But once I start using Designer 2.1, I need to keep moving forward (1.0 Designer does not understand every tweak/enhancement added over 5 years).