Good morning.
This is absolutely maddening... my sketch has now decided it will no longer compile!!!
On my word, the only adjustment whatsoever was to change the clock speed from 8mHz to 1mHz and disable B.O.D. (really wasn't terribly worried about a brown-out). Not a single character in the sketch was altered. I even double-checked against the copy posted by DrAzzy in a previous reply (who was kind intention was to show me how to post the code directly into the reply instead of an attachment).
Tried to get it to compile with the DrAzzy ATtinyCore for both ATtiny45_85 (Optiboot) board and ATtiny25/45/85.
No luck with either.
Also mentioned in a previous message was that IDE 1.8.10 could be buggy with certain parameters. I uninstalled 1.8.10 and installed the 1.8.9 version of Arduino and tried again. No apparent success or difference.
Setting preferences for verbose output produced a lengthy (and cryptic) error message. Despite advice to the contrary I am again going to attach the file instead of copying it here. It is just too large.
Kindly inspect same and advise.
Thank you for your help.