RAW DYNAMO ISSUE - Specified cast is not valid

Hello guys!

I’m praparing data modification modules in DYNAMO (Excel + Python), no connection to Revit this time.
And I have disturbing issue with DYNAMO (checked with 2.5… 2.8). Im using twice Watch block for the same output. One is ok but the other has warning “Specified cast is not valid.”

Any advice, please?
I have the same problem with other blocks, but this example is cleare. DYNAMO looks quite unstable.

Leszek Nowak

could you post the whole DYN please?

Hello Tom,

I have no Idea how =>
There are several python libraries, couple of extra modules and excel files as a data source and output. All in subfolders :slight_smile:


Tom, Usually problem disappears when I cut half of my nodes + file reload. This leads me to conclusion that could be memory management problem.

Could be - but we can’t tell without more insight.

Have you got any tips how to share project essentails on the formum? I have all files on OnDrive now.

You can try to post here but that may be too large for everything. You can also share the onedrive link as well - be sure to leave it open for all for at least a few weeks. Alternatively you can try another sharing service such as google drive, box, Dropbox, we transfer, etc.


please do share the link, interested to see whats going on here.

Sure, I will prepare seperate folder with this issue and I will let you know.