IDA 6.8 undo action

I'm using the IDA pro v6.8 dissembler. Is there an option to undo the last action (e.g. patching). In the IDA Pro v7.5 the undo is bidden to CTRL+Z but when i use this combination in IDA v6.8 just nothing happens. For some reason i have to use the 6.8, not 7.5 version. If there is no such an opinion in v6.8 maybe there is some plugin for that?