Certain versions are internal and may not be released because there may not be significant changes, if that's what you meant to ask about missing version sequences.
We try not to make any changes that render code from past SDK versions unusable. Slight tweaking may be necessary, of course. For example, the configuration BIN files etc would be backward compatible. But some new functions may be added to new releases that must be called.
There will be continued support for recent SDKs, especially in case of major flaws. However, we highly recommend using the latest SDKs because they usually contain patches/fixes from past versions - that is why they are new releases. The changelog should make things clear anyway.
Who is online
Users browsing this forum: Baidu [Spider] and 10 guests
Newbies Start Here
Are you new to ESP8266?
Unsure what to do?
Dunno where to start?
Start right here!
We also have a RTOS version and a MESH version too!
Complete listing of the official ESP8266 related documentation release by ESPRESSIF!
Must read here!