ALERT: Transaction Error. Exception thrown in contract code.

[john-light]

When I click New Order -> Buy and enter 5 DAI then the following happens:

1. MetaMask pops up an approval tx. I sign it.
2. Immediately a second MetaMask box pops up with the following error shown: ALERT: Transaction Error. Exception thrown in contract code.

This error sounds scary. Nonetheless, my order did seem to go through.

[osarrouy]

Yes I've seen this one too. Strangely it didn't occur on our local ganache chains ...

I'm gonna investigate further but my take is that the approve transaction has not been mined yet when initiating the openBuyOrder one thus leading Metamask to believe the transaction will fail ...

Once more this approval pre-hook is handled at the client level so gonna check with Brett.

[sohkai]

This isn't something we can solve; this is Metamask trying to be too smart for its own good. There's really no way to work around this, we either:

• Open two transactions at the same time
• Wait for the first one to be mined and then send the next transaction

We prefer the first so all the user action can happen at once.

[john-light]

@sohkai fwiw as a user I personally prefer the second option. It reduces confusion for me about this error message, in what order I should be signing the transactions, what if the second one is confirmed before the first one, etc.

[sohkai]

@john-light The problem with the second one is that on mainnet, your transaction might take ages to mine, and you'd probably prefer the pending transaction in the tx pool already rather than having to wait on the frontend.

We can perhaps make this experience better in the signing panel, where we could wait by default but still allow a user to immediately sign and send the second transaction if they like (knowing that their web3 provider might prompt them with a warning).

[osarrouy]

@sohkai @john-light I do feel that the actual solution is the less of a harm ... If we wait for the first transaction to be mined before we send the second and the user closes it browser tab then the whole chaining of transaction we be messed up.

This is a problem especially for approve pre-hooks since some ERC20s will revert it you try to re-approve a token whose actual allowance is not zero ...

@john-light Is it ok to close this issue for now since it's not really fundraising related ? Or maybe we wanna copy-paste in aragon/aragon before to keep track of the conversation ?

[john-light]

if it is not a fundraising specific error then it makes sense to me to close it