Lotus Notes 8.5.1 client will hang, and notes2.exe will spike the CPU at 100% after pasting a large paragraph, or editing a document with a lot of text
Client hang will occur, and can only be resolved by terminating Notes executables from Task Manager.
The cause of this problem is the new Spell Checker functionality introduced in 8.5.1. If there is a large amount of text with misspelled words, then the client hang will occur.
Lotus Notes 8.5.1
Resolving the problem
This problem has been reported to Quality Engineering in SPR ZHZH7RS9CP, and is fixed in 8.5.2.
As a workaround for earlier builds, you can either disable the new Spell Checker with the notes.ini parameter, SPELL_FORCE_LEGACY=1, or disable Instant Spell Checking prior to copying the text, or editing the document.
Another reported issue while working with the new Spell Checker was reported in Technote 1410078 titled, "Notes 8.5.1 client crashes when messages are forwarded while spell check is enabled", where a Lotus Notes Client crash would occur. This particular issue is fixed in 8.5.1 FP1.