Depends on what the issue actually was, there were different reports and manly based on guesses.
Simple example, Eurofighter program history:
The minimum acceptance was only for quick reaction interception roles and it went into mass production for 4 different air forces. The IOC which included some technical and weapon additions came later only and as you can see the FOC was achieved only years after the production start and that is not unusual, but common for most modern fighter developments. In nearly all cases of 4th gen fighter developments, they will be qualified mainly for a single role, while additional once and increased technical capability will be added later. The first Rafales were meant for carrier operations and only for A2A roles, it had limited optical and EW capabilities, which came only with the later F2 and 3 batches for the air force.
The same goes for JF 17 or J10 btw too and in the case of LCA the delays of the developments of certain parts, mixed up it IOC capabilities as well. It already has an integrated HMS, coupled with the R73, it has an LDP integrated as well as LGBs, so it already has capabilities which usually will be added only in later stages. If I'm not wrong JF 17 still has no LDP, HMS, nor any LGBs right? So LCAs IOC might be unusual and obviously delayed, but is by far not like you "think" it is.
you lose any which way try as hard as you can, now go cry in the corner f***face.
I was under the impression that only serial production planes can be declared operational.
