Expression Activity type 'VisualBasicValue`1' requires compilation in order to run

I know that most of you will probably point me back to this post

for the solution to my problem. But in truth, that post did not solve it. I needed to dig deeper.

The short story is that we converted a Windows - Legacy process to a Windows process in Studio 2021.10.6. As Windows - Legacy it worked great. When we converted it to Windows, were getting the error indicated in the subject.

As per the above post, we went through all the expressions in the offending workflow file and could not find a single one where the quotes were the wrong type of double quotes. We, litereally, spent about 2 weeks looking for the problem and could not find it to the point where we engaged UiPath Technical support… and they were also stumped.

But, I did find a solution. I’ll post it as a reply to this post and mark it solution so that others can find it.

So, the solution:

The problem was not in any of the VB expressions in any of the activities. All literal strings were properly wrapped in 0x22 quote characters.

HOWEVER… we had some activities where the developer had copied and pasted text from a word document to use as the Activity name. In that activity name, we had the offending quotes.


Looking at this on screen, it’s hard to see. And as you can see, the Message field was correct. The problem is in the label… those quotes are the wrong kinds of quotes. The compiler on publishing did not catch it nor did the Validation tool.

What I ended up doing to find this is run the automation with logging set to “Verbose” on the bot and I noted that this particular log activity faulted. Once I removed the offending quotes


My project started running perfectly without error.

I’m posting this solution hoping that someone else who is running into the same problem will not spend two months banging your head on a brick wall only to discover that your activity name is causing the issue.

Happy automating!

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