The type of board you are using.

ATtiny85 board (ATTinyCore by Spence Conde)

The boards name or FQBN (e.g. esp8266:esp8266:d1_mini:eesz=4M3M,xtal=80) for unspecified board.

No response

The board manager URL used for unspecified board.

https://

What IDE are you using?

Arduino IDE

What IR protocol are you using?

NEC

Pin(s) used for IR-receive, if not default.

Arduino pin number: default

Example(s) you have checked while hunting the bug.

• SimpleReceiver
• ReceiveDemo
• SendRawDemo
• ReceiverTimingAnalysis
• TinyReceiver
• TinySender
• ReceiveAndSend
• SimpleSender
• SendDemo
• SendLGAirConditionerDemo
• UnitTest
• Other - please specify below
• I checked, if at least one of the examples was working.

Example(s) to reproduce the issue.

• SimpleReceiver
• ReceiveDemo
• SendRawDemo
• ReceiverTimingAnalysis
• TinyReceiver
• TinySender
• ReceiveAndSend
• SimpleSender
• SendDemo
• SendLGAirConditionerDemo
• UnitTest
• Other - please specify below

The library version you are working with.

• I use the latest Arduino library version and verified this!
• I use the latest repo version (download link) and verified this!

What are the steps to reproduce this issue?

use TinyReceiver example with callback enabled:
#define USE_CALLBACK_FOR_TINY_RECEIVER

What happens?

callback handleReceivedTinyIRData() is not being called

The serial output which indicates the error happened.

No response

What were you expecting to happen?

handleReceivedTinyIRData() should have been called

Additional context.

TinyIRReceiver.hpp
line 154 is:
extern void handleTinyReceivedIRData();

I think it is mispelled, and should be:
extern void handleReceivedTinyIRData();

Did not specify a protocol, so I guess it is NEC by default.
I guess the bug was introduced with changes in v4.2.1
This example and my stuff worked with a previous version (did not note before lib update)

Thank you for this great library!
And happy holidays :)

Final checklist for the bug report.

• I have read the README.md file thoroughly
• I have searched existing issues to see if there is anything I have missed.
• I have browsed the examples for one, that matches my use case.
• The title of the issue is helpful and relevant.