InfoPath Dev

I want to store values of two repeating tables into one text box in SharePoint form library.I have two repeating tables with text fields. I concatenated the values of each row of each repeating table into one text box field using the formula: concat("-", field2)and I promoted this concat field of repeating field select "merge", then I created a separate text field in the form and enabled the multiline option, and trying to set it to store all the values from the text boxes of this two repeating tables via workflow .I mean suppose the concatenated field of repeating table 1 is "X" and for the second repeating table is "y" and the destination text field is "T" then I use action "set field value" in workflow to set field T. the action is: set field T to ....(that I choose ... and select X then enter and select Y ) like this: X(in one line) Y(in the other line) It works fine until two days ago the workflow was canceled. one form was submitted fine but another form did not. I reduce the value which user inserted for X and it works but when I try to submit the first form again to show it works, the first one that was once submitted successfully also canceled and when I reduced the two rows of the first repeating table (value X) workflow runs. I wonder why this happens and I don't know how many characters it supports because when using multiline, the limitation of characters is disabled. Can anybody help me fix this?

Hi everybody, I fortunately found a way to solve this problem and I think it's good to write it here for others. for solving this issue, I decide to change the properties of field in form library after promotion ,I mean the properties of textbox (destination field) must be changed not in the form only It means you must set the field multiline in form and promote the the field then go to the form library in share point site and in document settings choose the promoted field and change the field from single line of text to multiple line of text and set the lines or choose unlimited line. I hope this is helpful.