Hi, can you include the full error message and versions of pymc3 and theano you are using? It’s much more probable we’ll be able to help if you do so.
Note that you can use markdown to format your post, i.e. three backticks ` for code blocks so that indentation is preserved, > is intended for highlight/quote blocks instead. And in addition, Discourse also has math support and some special tags for things like quote responding or creating dropdowns. If the error message is too long and would clutter the post, use a dropdown to make it available yet hidden by default. You can do so from the gear icon, the rightmost one or directly writing:
[details="Traceback"]
Error trance here, formatted as a code block.
[/details]