Invalid character error

Hi,
Can you upload the whole project (without the .exe) and I'll try and have a look.
I seem to recall having a similar problem a couple of years ago - not sure I can remember if / how I fixed it though.
Derek.

Hi,
I've not been able to see anything obvious and the error message isn't all that helpful. 
I think this is a question for Dmitry.
The only other course of action might be to use an earlier version of forms.xml, but depending on the number of changes you've made recently, I don't know how realistic this is.
Derek.

Thanks, @cbnbg. Making correction in XML file using Notepad++ was a daunting task, that I was unable to perform. I recreated the new forms from an earlier version of the project as suggested by Derek and the error disappeared. However, the joy is short-lived as another error has appeared. On clicking a button, whose action is to show a form, error pops up: "" is a not valid integer value  . How to resolve this issue? Redoing the project means more hours lost.

Happy new year Derek.
I have attached the project. Initially, the application again ran ok when saved to a new folder, but soon the same error appeared. Please have a look.

Hello Eyeman
Happy New Year to you too.
I think your problem lies with your data,  There are records in AA_001_REC_PATIENT_REG and AA_005_REC_BILLING with missing foreign keys and missing data (please see the screen shots in the attachment).  Or use something like SQLITESTUDIO to have a look at the raw data and you will see the problem.  If you delete these records, you no longer get the error.
Why the data had missing key information is, of course, the more important issue (although perhaps it was just test data you were using and that's why it's incomplete - let's hope so).
Regards,
Derek.