1. Be sure you have updated 2017
2. If the client is locked - Backup - Remove lock - do proforma
3. Sometimes one or more input items get garbled. Unlock, view return, try proforma. If that fails, use Ctrl + W to visually look at all code and see if anything looks weird, ░╣ꜩ kind of stuff. Delete these items and re enter.
yes always check for updates with invalid format first thing and try again second step if still doesn't work check data path through setting> options >setup third step check for pre filters then fourth step is to check for invalid characters in clients by going to detail>switch to batch mode if all else fails rename the client file by adding .OLD to the end of it by following the data path but also make sure that its not marked a final return these will not proforma at all